Responses
There are two stories here. Kadokura Kouhei is the older brother uke in the first story.
The uke in the second story is called Imai. I don't know his full name.
Thank you soo much for clarifying!
(づ￣ ³￣)づ
So...is "big brother" the same character in Kamakere as the "big brother" in Uchi wa Futago de Teippai? If so, did he go on a business trip or something and then while the twins stayed at home he was out getting laid by his senpai? There's no explanation or anything so I'm lost af.