Why does SSJ4 go shirtless?

[Captain Strawberry]

I dislike this part of the transformation, you out of nowhere, lose your shirt/upper garment...

[dbgtFO]

The real question is why they get pants and why SS4 Gogeta gets the fusion vest.
The show doesn't explain, as per usual, so we are left with making assumptions and perhaps Goku and Vegeta subconsciously triggered some innately magical power, that produced clothes, they'd like to wear.

[Chuquita]

Fan-service, I guess. Ssj4 isn't my cup of tea, but I can understand how it would be others'.

GT had so little fan-service up to that point compared to Z that the final arc really did feel like they were desperate to grab lost interest.

[TheDevilsCorpse]

The real question is why they get pants and why SS4 Gogeta gets the fusion vest.

Why wouldn't Gogeta get the fusion vest? It's not like the transformation prohibits a shirt, in that trying to put one on after going SS4 would cause the clothing to incinerate on contact.

If they had been able to fuse at any of the lower levels and then went Super Saiyan 4, I could see the vest disappearing. But they fuse while already at SS4, to the technique's "magic" is being applied over the transformations.

[dbgtFO]

The real question is why they get pants and why SS4 Gogeta gets the fusion vest.

Why wouldn't Gogeta get the fusion vest?

Cause DBZ filler had naked Goten and Trunks merging and that didn't produce a fusion vest, nor clothes for that matter and given neither Goku nor Vegeta were wearing something on their upper body, well I have to question that. Given that they somehow produce clothes as SS4s, I guess my speculation could apply here as well.

[Lord Beerus]

A wizard did it.

[Kuririn Fan]

" Because i'm a monkey!" - TFS Kai Vegeta, Age 762
It's GT, dude, the same show that has kid Goku all grown up when he's a Ss4.

[mikey4111]

Because it's sexy, helps get the saiyan laid.

[Xeztin]

I'd like to think going from Golden Oozaru to SSJ4 creates a new body because the Golden Oozaru and Goku/Vegeta's normal body's weren't strong enough to handle the power. That could explain the shirt missing since it's a different body and when they return to base they return to their normal bodies. It doesn't explain where the pants and such come from, but I don't understand where the darn Vest in fusion comes from either. I don't think any of these things are meant to be deeply looked into because that just would complicate things for younger readers/viewers.

[Cipher]

The shirts restrict their true power.

[Pocket-God]

Well......I seriously wish it was the pants that was missing in the SSJ4 form buuut that's probably just me

[Soppa Saia People]

I'd had always assumed it was like the hulk.

[Cetra]

Because nudity makes them stronger.

An easy-inuniverse explanation: Their potential of controlling energy has come so far that they can convert it to matter. So when they transform they would not wear anything but they at least materialize the stuff they need for battle.

[TheatreStyleKai]

Do you have any idea how uncomfortable it would be to wear a shirt over fur? I'm sure SSJ4 Vegeta is chaffing something fierce every time he moves in those tight ass pants.

[Zillamon51]

The first time Goku transformed SS4, he should have been naked. We know he has no inhibitions against it. He would stand tall and proud before Baby, his manhood strategically hidden by some Austin Powers-like camera angles. Everyone else would be terribly awkward / embarrassed. Then Supreme Kai pops in, says "Can't have that! Here's some magic pants!" Plot hole closed.

[apex_pretador]

Because shirtless is goku's ultimate powerup.

Every time in a movie, when goku loses his shirt, he overcomes the odds to become john cena of toei & since in GT , he's already far outclassed by his opponent's weaker forms, he needs the shirtless power to be stacked up above a new transformation.

See like this in multipliers:

Base goku - 1
SS goku - 2 (2x)
SS3 goku - 8 (4x)
SS4 goku - 20 (2.5x)
Shirtless - 1000 (50x)

Since his shirtless multiplier is bigger than his base to SS4 multiplier, he'd obviously go that route.

On vegeta, well, he is always one step behind goku, so he also got the same treatment.

EDIT: Not to mention that in SS4, the shirtless multiplier can be achieved without getting terribly outclassed by the opponent, who doesn't even flinch on your attacks.

[Hellspawn28]

Out of Universe Answer - They needed a cool design to draw in ratings and to sell toys. SSj4 looks cool and can make your 6 year old watching GT at the time to ask their parents to buy a action figure of it.

In Universe Answer - I think the power going into Oozaru and SSj4 causes the shirts to rip into pieces. So they just have pants similar to the Hulk.

[Kamiccolo9]

In Universe Answer - I think the power going into Oozaru and SSj4 causes the shirts to rip into pieces. So they just have pants similar to the Hulk.

Then I suppose the next question would be "why does reverting to base make the clothes grow back?"

[Skar]

I always wondered why they needed pants in SSJ4. I mean they're covered in fur so it would look something like this:

Spoiler:

[Captain Strawberry]

Do you have any idea how uncomfortable it would be to wear a shirt over fur? I'm sure SSJ4 Vegeta is chaffing something fierce every time he moves in those tight ass pants.

But it's magical fur.