He is Michi's dad (= oto-san). Michi is a little blond kid who is Hikari's friend. They start appearing in the third volume. As the story progresses we learn that "Oto" is an Omega and deeply distrustful towards alphas. He nearly stopped all contact with Masaki and the kids when he learned that Masaki is married to an alpha (Hiro).
Vol 3
there are two types of people
Haha, I feel kinda like I got dissed xD But fair enough.
thank you so much
thank you (●'◡'●)ﾉ
where can I find Oto`s Story? i dont remember him T-T