Replying...
Intro. Giyuu 21 years old is the gymnast of Kimetsu and Giyuu also liked him and he as a male student who also beat and learned quite well, but until one day Giyuu was attacked by an attacker and giving him a tablet to change his size into a 10 -year -old boy (Giyuu will keep it secret and not tell me, not let me know)

Tomioka Giyuu

@Naru