Osake to Senpai Kanojo to no Amaama Doukyo Love Comedy wa Hatachi ni Natte kara

"It's about time for us to move in together.” On the day Takashi turned 20, that's what his girlfriend, Momiyo-senpai, said to him. Their new zero-distance lovey-dovey cohabitation life is about to begin! Momiji loves to drink, but when she gets a little drunk, she becomes even more aggressively seductive… Takashi's rational thoughts are on the verge of breakdown! The two love each other dearly, and whether they are drinking at home or out, they boldly explore their relationship by flirting with each other in every possible way! (Source: HJ Bunko, translated)