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Official Boy Genius Store Shop Boy Genius Merch I Don't Know Why I Am The Way I Am Demon Crew neck

Official Boy Genius Store Shop Boy Genius Merch I Don't Know Why I Am The Way I Am Demon Pullover Sweatshirt

Rated 4.67 out of 5 based on 3 customer ratings

(4 customer reviews)

Original price was: $21.99.Current price is: $19.99.

Estimated delivery dates: Jul 27, 2026 - Aug 4, 2026

Style

Color

Size

Clear

Sizing chart

Don’t have your favorite color, size? Please contact us directly if you would like to have your own one.

Unisex Standard T-Shirt

Size	Chest Width	Shirt Length
S	18 in	28 in
M	20 in	29 in
L	22 in	30 in
XL	24 in	31 in
2XL	26 in	32 in
3XL	28 in	33 in
4XL	30 in	34 in
5XL	32 in	35 in

Note: Allow for a tolerance level of 1 inch

Unisex Hoodie

Size	Chest Width	Shirt Length	Sleeve Length
S	20 in	27 in	33.5 in
M	22 in	28 in	34.5 in
L	24 in	29 in	35.5 in
XL	26 in	30 in	36.5 in
2XL	28 in	31 in	37.5 in
3XL	30 in	32 in	38.5 in
4XL	32 in	33 in	39.5 in
5XL	34 in	34 in	40.5 in

Note: Allow for a tolerance level of 1 inch

Unisex Sweatshirt

Size	Chest Width	Shirt Length	Sleeve Length
S	20 in	27 in	33.5 in
M	22 in	28 in	34.5 in
L	24 in	29 in	35.5 in
XL	26 in	30 in	36.5 in
2XL	28 in	31 in	37.5 in
3XL	30 in	32 in	38.5 in
4XL	32 in	33 in	39.5 in
5XL	34 in	34 in	40.5 in

Note: Allow for a tolerance level of 1 inch

Men's Zip Hoodie

Size	Chest Width	Shirt Length	Sleeve Length
S	19.25 in	27 in	33.5 in
M	21.25 in	28 in	34.5 in
L	23.25 in	29 in	35.5 in
XL	25.25 in	30 in	36.5 in
2XL	27.25 in	31 in	37.5 in
3XL	29 in	32 in	38.5 in

Note: Allow for a tolerance level of 1 inch

Men's Long Sleeved T-Shirt

Size	Chest Width	Shirt Length	Sleeve Length
S	18 in	28 in	33.5 in
M	20 in	29 in	35 in
L	22 in	30 in	36.5 in
XL	24 in	31 in	38 in
2XL	26 in	32 in	39.5 in
3XL	28 in	33 in	39.5 in
4XL	30 in	34 in	39 in
5XL	32 in	35 in	40.5 in

Note: Allow for a tolerance level of 1 inch

Men's V-Neck T-Shirt

Size	Chest Width	Shirt Length
S	18 in	28 in
M	20 in	29 in
L	22 in	30 in
XL	24 in	31 in
2XL	26 in	32 in
3XL	28 in	33 in

Note: Allow for a tolerance level of 1 inch

Men's Tank Top

Size	Chest Width	Shirt Length
S	18 in	28 in
M	20 in	29 in
L	22 in	30 in
XL	24 in	31 in
2XL	26 in	32 in
3XL	28 in	33 in

Note: Allow for a tolerance level of 1 inch

Ladies Long Sleeve T Shirt

Size	Chest Width	Shirt Length
S	18 in	28 in
M	20 in	29 in
L	22 in	30 in
XL	24 in	31 in
2XL	26 in	32 in
3XL	28 in	33 in

Note: Allow for a tolerance level of 1 inch

Ladies T Shirt

Size	Chest Width	Shirt Length	Sleeve Length
S	17.25 in	25.5 in	13.25 in
M	19.25 in	26 in	14 in
L	21.25 in	27 in	14.75 in
XL	23.25 in	28 in	15.75 in
2XL	25.25 in	28.5 in	16.75 in
3XL	27.25 in	29 in	17.5 in

Note: Allow for a tolerance level of 1 inch

Ladies Hooded Sweatshirt

Size	Chest Width	Shirt Length	Sleeve Length
S	20 in	26 in	32 in
M	22 in	27.5 in	33 in
L	24 in	28 in	34.5 in
XL	26 in	29.5 in	35.5 in
2XL	28 in	30 in	37 in

Note: Allow for a tolerance level of 1 inch

Ladies Tank Top

Size	Chest Width	Shirt Length
S	15 in	27.56 in
M	16.1 in	27.95 in
L	17 in	28.35 in
XL	18.1 in	29.13 in
2XL	18.9 in	29.53 in

Note: Allow for a tolerance level of 1 inch

Ladies V Neck T Shirt

Size	Chest Width	Shirt Length
S	17.25 in	25.5 in
M	19.25 in	26 in
L	21.25 in	27 in
XL	23.25 in	28 in
2XL	25.25 in	28.5 in
3XL	27.25 in	29 in

Note: Allow for a tolerance level of 1 inch

Youth T Shirt

Size	Chest Width	Shirt Length	Sleeve Length
XS (4-5 years)	16 in	20.5 in	13.5 in
S (6-7 years)	17 in	22 in	14.5 in
M (8-9 years)	18 in	23.5 in	15.5 in
L (10-11 years)	19 in	25 in	16.5 in
XL (12-13 years)	20 in	26.5 in	17.5 in

Note: Allow for a tolerance level of 1 inch

Mug

Twill Cap

360 Crown	Front Crown
22.24 in	12.6 in

Visor's Length	Visor's Width
6.69 in	4.53 in

Note: Allow for a tolerance level of 1 inch

Tumbler

Cloth Face Mask

Baseball Jersey Shirt

Size	Length	Bust	Shoulder
S	29.92 in	34.65 in	14.96 in
M	30.31 in	37.8 in	16.14 in
L	30.71 in	40.94 in	17.32 in
XL	31.1 in	44.09 in	18.5 in
2XL	31.5 in	48.03 in	19.69 in
3XL	31.89 in	51.97 in	20.87 in
4XL	32.28 in	55.91 in	22.05 in
5XL	32.68 in	59.84 in	23.23 in

Note: Allow for a tolerance level of 1 inch

Basketball Jersey Tank

Size	Length	Bust
XS	27.6 in	39.2 in
S	28.4 in	40.8 in
M	29.2 in	42.4 in
L	30 in	45.6 in
XL	30.8 in	48 in
2XL	31.6 in	50.4 in
3XL	32.4 in	52.8 in
4XL	33.2 in	55.2 in
5XL	34 in	57.6 in

Note: Allow for a tolerance level of 1 inch

Basketball Suit

Size	Length	Bust	Shoulder	Pant Lengths	Waist	Hip
XS	24.8 in	36.22 in	13.39 in	18.11 in	23.62 in	38.58 in
S	25.79 in	37.8 in	13.78 in	18.9 in	25.2 in	40.16 in
M	26.77 in	39.37 in	14.17 in	19.69 in	26.77 in	41.73 in
L	27.76 in	40.94 in	14.57 in	20.47 in	28.35 in	43.31 in
XL	28.74 in	42.52 in	14.96 in	21.26 in	29.92 in	44.88 in
2XL	29.72 in	44.09 in	15.35 in	22.05 in	31.5 in	46.46 in
3XL	30.71 in	45.67 in	15.75 in	22.83 in	33.07 in	48.03 in
4XL	31.69 in	47.24 in	16.14 in	23.62 in	34.65 in	49.61 in
5XL	33.07 in	48.82 in	16.54 in	32.28 in	36.22 in	51.18 in

Note: Allow for a tolerance level of 1 inch

Hawaiian Shirt

Size	Length	Bust	Sleeve
XS	27.17 in	37.8 in	16.54 in
S	27.95 in	40.94 in	17.32 in
M	28.74 in	44.09 in	18.11 in
L	29.53 in	47.24 in	19.09 in
XL	30.31 in	50.39 in	19.88 in
2XL	31.1 in	53.54 in	20.87 in
3XL	31.89 in	56.69 in	21.65 in
4XL	32.68 in	59.84 in	22.64 in
5XL	34.25 in	62.99 in	24.02 in

Note: Allow for a tolerance level of 1 inch

Express your individuality with a cozy sweater inspired by modern music culture and everyday streetwear fashion. Designed for comfort and effortless styling, it pairs easily with jeans, joggers, or layered outfits for casual outings, concerts, or relaxing weekends. Its timeless fit and eye-catching design make it a great addition to any fan’s wardrobe while offering versatile wear throughout the seasons. Whether for yourself or as a thoughtful gift, Official Boy Genius Store Shop Boy Genius Merch I Don’t Know Why I Am The Way I Am Demon Sweater delivers stylish comfort with a unique fan-inspired look.

T Shirt:

100% Premium polyester which is ultra-soft and incredibly comfortable.
Fabric is durable and resistant to wrinkles, shrinking, and mildew.
Features ensure long-lasting color vibrancy even after machine washing.

Care Instruction:

Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
Do not use bleach
Do not iron
Do not dry clean
Do not tumble dry

Hoodie:

Material: 90% polyester, 10% spandex.
The soft sherpa fleece on the inside is extremely soft and cosy.
Flat contrasted drawstring, Front pouch kangoroo pockets. Elastic waist and cuffs.
Garment care: Machine washable in gentle, recommend hand wash in cold water, line dry, do not bleach, low iron if needed.

Care Instruction:

Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
Do not use bleach
Do not iron
Do not dry clean
Do not tumble dry

Sweatshirt:

95% Polyester, 5% Spandex.
Dye-sublimation printing, colors will never be faded or peeled.
It is used to react to your body's temperature to keep you warm in the winter and cool in autumn.

Care Instruction:

Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
Do not use bleach
Do not iron
Do not dry clean
Do not tumble dry

Zip Up Hooded Sweatshirt:

Material: 10% Cotton, 90% Polyester.
Sherpa lining can provide better insulation and extra down-like warmth.
Relaxed Fit – generously sized for ease of movement.
This jacket is custom-designed in a classic style and is a must-have item in the wardrobe.

Care Instruction:

Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
Do not use bleach
Do not iron
Do not dry clean
Do not tumble dry

Long Sleeve T Shirt:

100% Premium polyester which is ultra-soft and incredibly comfortable.
The soft and stretchy fabric gives you comfy all day long, is high quality, quick-drying, and suitable for autumn and winter.
Long Sleeve Shirts have been in fashion for ages and they will always be an essential wardrobe staple for gentlemen.
Whether you want to go out for sports or just want to put them on as leisurewear, whether you want to pair them with a trouser or shorts, they always look great and offer an easy choice for all occasions!
Suitable for special occasions such as Christmas, birthdays, celebrations, and housewarming gifts.
Print: Dye-sublimation printing.

Care Instruction:

Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
Do not use bleach
Do not iron
Do not dry clean
Do not tumble dry

Youth T Shirt:

100% Premium polyester which is ultra-soft and incredibly comfortable.
Fabric is durable and resistant to wrinkles, shrinking, and mildew.
Features ensure long-lasting color vibrancy even after machine washing.

Care Instruction:

Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
Do not use bleach
Do not iron
Do not dry clean
Do not tumble dry

Hawaiian Shirt: The Hawaii shirts are really the ideal choice to wear in the tropical atmosphere when the summer and the holiday are coming so soon. They are cool and more interesting as compared to typical mono-color clothes. They are casual and formal at the same time.

Material: 95% Polyester - 5% Spandex
Printing technique: dye-sublimation

Baseball Jersey Shirt: It is not only extremely soft to the touch but breathable as well. Our jersey is printed on sustainable fabrics so do not worry about shrinkage, never flake, peel, or crack. Machina washable, tumble dry on low heat, no bleach.

Material: 92% Polyester - 8% Spandex
Printing technique: dye-sublimation

Basketball Jersey Tank: It is not only extremely soft to the touch but breathable as well. Our jersey is printed on sustainable fabrics so do not worry about shrinkage, never flake, peel, or crack. Machina washable, tumble dry on low heat, no bleach.

Material: 90% polyester + 10% spandex.
Moisture-wicking properties.
Ensures durability, side seams a stylish classic fit.
Suitable for any sport activities, yoga session.
A good choice of gift for your loved one who like working out.

Basketball Suit: Our basketball suit is perfect for fans, featuring a lightweight construction with a V-neck collar, sleeveless design and flat lock seams that provides all day comfort. Players embraced the accessorized look more as an expression of personal style than anything else. Made of a lightweight polyester air-mesh, this basketball clothes set will keep you cool during the warmer months, just in time for playoff season. This suit was made with comfort in mind. Cut a bit slim to give you the most flattering fit possible.

Material: 100% Polyester
Printing technique: Digital Printing

Twill Cap:

Our hats are available in a variety of colors and are suitable for both men and women. They provide excellent sun protection and are ideal for any outdoor activity! With adjustable snap back construction (one size fits all), everyone in your family can now wear these hats!
Add style and personality to your hat collection with a custom printed classic cap.
Constructed with 100% premium polyester that’s lightweight for maximum comfort and breathability.
Universal Fit: One size fits most with an adjustable snapback closure.
Printing technique: Sublimation

Care:

Do not bleach
Do not wash

4 reviews for Official Boy Genius Store Shop Boy Genius Merch I Don’t Know Why I Am The Way I Am Demon Sweater

Rated 4 out of 5
Dylan Max (verified owner) – July 2, 2026
Best experience possible on the market. Easy to use web-site, good prices, strongly recommended to all my friends.
Rated 5 out of 5
Ryder Amanda (verified owner) – July 2, 2026
I am very happy with the products I received, that came very quickly and everyone that I got them for loved them.
Rated 5 out of 5
Michael Caridwen (verified owner) – July 2, 2026
Thank Shop, gave me a wonderful shirt.
Rated 5 out of 5
Edward Nathaniel (verified owner) – July 2, 2026
It was a wonderful shirt. It is beautiful, the quality is good, the print is superb

Only logged in customers who have purchased this product may leave a review.

Production Time: All orders are processed within 2 - 4 business days. Particularly for 3D and All Over Print shirts, production time can be up to 7 business days.
Processing Time: It takes 1 - 2 days to ship your order to our warehouse, put your name and address on it and ship out.
Delivery Time: Delivery time is equal to production time plus processing time and shipping time depending on the region, country and shipping package.
Shipping Cost:
- The Standard shipping price is $4.99 (4-8 business days).
- The Ground shipping price is $10.99 (3-6 business days).
- The Fastship shipping price is $19.00 (2-4 business days).
- International shipping price is $14.99 (2-3 weeks).
- Order 2 items or $64.99 for our FREE SHIPPING (USA Only)
- Please Note: Estimated delivery time does not include production time 2-7 business days.
- Business days: From Monday to Friday excluding holidays.
Return & Exchange: If for some reasons you are not happy with your purchase, we will happily work with you to correct the problems. Items can be return/exchange and get Refund within 30 days of delivery date.
Tracking Number: When available, we will send you the tracking number with the confirmation email so that you can track the package online.
If you have problems with shipping please send to email: [email protected]