Oogaki is the nephew of Tooru's ex wife who came to help him move after his divorce. Tooru (straight) and Oogaki (gay) met each other in a gay bar that Tooru's friend owns where they chatted. It was later when they realized that they were going to become family. However, now that they are no longer related, Tooru feels that he is allowed to fall in love with Oogaki.
After divorcing his wife, Tooru was all alone. The only one he’d been relying on was his (now ex-) wife’s nephew, Masachika. With his connection to Masachika now lost, Tooru’s loneliness grew until one day…?https://www.nicoobook.com/p/116659