Mibu no Tsugai  

壬生の番い

In the Okita household, Sousuke, who is the only omega in his family, faced mistreatment due to his sexual orientation. Following an overdose on heat suppressants, he passed out and time-traveled to the late Edo period. There, he encountered Toshizou Hijikata, who was the Vice Commander of the Shinsengumi. As a result, Sousuke was taken into custody under the name "Souji Okita." With no other choice but to live with the Shinsengumi, he gradually developed feelings for Hijikata. However, Hijikata persisted in confusing Sousuke with Souji Okita.