My MHA son and some self-indulgent ship art :3
His quirk is tied to his emotions, so at times of angry outbursts, moments of immense sadness/frustration or sudden shock/surprise, he will grow far too fast for his body to catch up, making muscles stretch too far too fast and cause pain and soreness (hence why he’s holding his neck like that in the first photo and why he’s trembling in the second). Monoma will copy his quirk to help him calm down when he gets too big to talk to normally. He’s nice company when he’s not trying to ragebait.
His hero name refers to the Japanese yokai, a small, small octopus that can grow to horrifying size to swallow ships whole. This is in reference to how Mana can both shrink very small and grow very large, it shows his range while also just giving him a cool hero name.
Also he is in fact Renji Abarai’s younger brother in the MHA universe but I haven’t figured out his quirk yet, ok bye— 🏃♂️