Started as a two-part oneshot about a guy accidentally transported to an Otome game by his sister. To get out, he needs to clear a love route but he tries his best to find another way.
Summary from Niconico:
Because of his little sister, high school student Tarou (alias) is transferred to an otome game as the heroine. The more he tries to avoid the handsome love interests, the further he advances into their love routes!
In the end, will he be able to return to his original world?!
And will he be able to protect his chastity?!