Younger Girlfriend [DL Version]

Synopsis

“When I grow up, I’ll become Big Brother’s bride.” A promise of the sort that rarely comes true in this world. Yuusuke Yanagimoto, a rookie teacher and the protagonist, had long since accepted that this promise made in the distant past would never be fulfilled.

Then one day, Ayane Aizaka, a young relative with a significant age gap, visits his apartment and says to him: “I’m old enough to get married now. …Will you make me your bride, just like you promised?”