Responses
Spoiler ~~~~~~
http://www.mangago.zone/read-manga/nekoka_danshi_no_shitsukekata/mh/manga/nekoka_danshi_no_shitsukekata/v05/c025/pg-21/
They are. It's mentioned in a phone call from Michiru's Mom. The dad is part wildcat, part lion.
Actually Shiou and Michiru are related by blood or not?!??? I'm really confused but the story is good