Officially described superpower
He can fit an item into a bag that is exactly the right size for it.
What remains unknown
No inventory bonus, capacity value, or playable ability details are confirmed on the English profile.
This record does not infer combat roles, friendship rewards, upgrade paths, or final launch behavior from a short profile.
Profile scope
The official page currently provides a compact character introduction and a “Useless Superpower” description. That wording is worldbuilding; it does not, by itself, establish a complete playable ability specification.