179cm He has blue eyes and white hair in a tidy bob cut. He wears a blue and white turtle neck.
He is very caring, even so far called like a mother in the webcomic. It seems that he has a violent side to him, however, as one of Osu's servants mentioned Number 1 being a punk in the past. One of these stories includes Number 1 knocking out three of Osu's father's teeth out by throwing a chair at him.
- Immortality: Number 1's species is immortal, unable to get sick, injured, or get killed. Any physical wounds their species receives will be restored immediately, along with severed body parts attaching themselves back together.
- Healing: Number 1, along with his siblings, possesses more powerful healing abilities than any other healer in SPOON. This is due to the siblings being immortal, meaning the life energy required for healing never decreases.