Hideki Nishimura, who plays the Legendary Age game under the pseudonym Rusian, vowed to renounce online marriages after confessing to a girl that he claimed to be a boy in real life.

After mustering up the courage to propose to a girl in an online game, naive otaku Hideki "Rusian" Nishimura is devastated when she flat-out rejects him. To make matters worse, the girl reveals that she is actually an older man in real life. With his dreams crushed and his heart broken, Rusian comes to an abrupt decision in the midst of his raging fit: he will never trust another girl in an online game again. Years later, Rusian is now in a guild with three other players, one of whom possesses a female avatar by the name of Ako. Ako is deeply in love with Rusian and wants to marry him. Although he entertains the possibility that she might be a guy, Rusian accepts her proposal, claiming that her gender does not matter as long as she is cute in-game. However, after a discussion between the guild members that led to all of them having an offline meeting, Rusian finds out that Ako, along with the other members, is not just a girl but also his schoolmate.—MAL Rewrite

Ako Tamaki has everything she could ever want: a wonderful husband, a cute outfit, and a guild filled with great friends. The problem? It's not reality. It's all in the online world of LA-aka Legendary Age. And when her guild meets IRL, her inability to discern between the real and online world becomes a problem. Can she trade magic spells for social skills, or will she forever be an IRL n00b?—Funimation

After Hideki Nishimura confesses to a girl online, he is shocked when she turns out to be a boy. Traumatized, he swears to never trust any "girl" players. That is, until one confesses to him. Ako Tamaki is a beautiful loner who has trouble differentiating between what's reality and the online world she spends so much of her time in. Can Hideki and his guild friends help fix socially inept Ako?—Crunchyroll