The Anime Lad
Nasa meets Tsukasa on the day of his high school entrance exams and is hit by a car. After she helps him, he confesses. She agrees to date him only if he will marry her first. A year later, after Nasa turns eighteen, Tsukasa returns and their married life begins. Dating order has been adjusted.
Super Eyepatch Fox
Nasa meets Tsukasa, survives a car accident, and confesses immediately. Her answer comes with one condition: marriage first. She returns after he turns eighteen, and the two begin a life together while still carrying the mystery and awkwardness of near-strangers. Commitment arrives before familiarity.
Gigguku
Nasa gets hit by a car on the day he meets Tsukasa and still finds enough momentum to confess. Then she answers with MARRIAGE FIRST. A year later she reappears once he is eighteen, ready to begin. The setup takes every slow romantic timetable, folds it in half, and lets two near-strangers start from the newlywed end!
Father's Basement
The premise piles sweetness and coincidence high enough to test anyone’s tolerance. Its one clean structural idea is starting with commitment instead of postponing it. Nasa confesses almost immediately, Tsukasa makes marriage the condition, and she returns after he turns eighteen. Their unfamiliarity remains, so the ordinary work of knowing another person still has somewhere to go.