決まる
きまる · kimaru · JLPT N4 · verb-godan
to be set
🔨 決 = decide; -maru = it happens by itself: kimaru = gets decided
Pair it with 決める (kimeru), to decide something. The -eru form takes an object: you decide it. The -aru form has no object: the matter ends up settled. Same pattern as 始める/始まる and 止める/止まる.