Kekkon Suru tte Itta Yone?

When he was younger, the protagonist made a seemingly innocent promise to his childhood friend: they would get married once they both turned eighteen. At the time, it felt like nothing more than a sweet vow between two kids who were inseparable. However, as the years passed and he grew older, observing the daily realities of his own family's household led him to a grim realization—marriage is an absolute nightmare. Armed with this newfound dread, he desperately wanted to back out of their childhood pact, but by then, the wheels were already in motion, and it was far too late to simply walk away. The true source of his panic, however, is not just the institution of marriage itself, but the person he promised it to. His once-familiar childhood companion has blossomed into a deeply unhinged young woman whose obsessive attachment defies all reason. Far from the innocent girl he once knew, she has transformed into an overwhelming force entirely fixated on making their long-ago promise a reality. Now trapped by his own words, the protagonist finds himself facing a terrifying dilemma: how does one escape a bride-to-be who has completely lost her mind and refuses to let him go?