be hooked on; fall intoUsed with に to describe being absorbed in or addicted to something, as in a hobby or food, or falling into a trap. The polite written form is はまっている; はまる is often written in katakana as ハマる in casual contexts.
JA: 最近、私は日本の歴史にはまっている。
EN: Recently, I've been hooked on Japanese history.