Kou and Yuki (My Wife Is A Man)
The married couple from the manga

“My Wife Is A Man” (おとこのこ妻 ; Otoko no Ko Tsuma) by Kurisutaruna Yousuke

Its a refference to the volume 1 cover.

‘R-18’, ‘trap’, ‘女装少年’, ‘女装男子’, ‘男の娘’, ‘腐向け’, ‘アナル’, ‘中出し’, ‘セックス’, ‘おとこのこ妻’