Artist, mangaka. The author of O/A.
Also known as “Watarai with a reputation for his after sex art” (事後に定評のあるわたらい).
Pen-name as a mangaka: 渡会 けいじ (Watarai Keiji)
Doujin & pixiv nickname: わたらい (Watarai)
Circle name: 御茶ノ水木人会 (Ochanomizu Mokujin-kai) (the other member: Yamamura Hitsuji)
Site name: Upper Ground