慣れる
なれる · nareru · JLPT N4 · verb-ichidan
to grow accustomed to
👟 nareru: after enough use it feels NAtural, like a broken-in shoe
慣 = heart 忄 + 貫 (to pierce, run through): something has run through your heart so many times it no longer surprises you. Same kanji as 習慣 (shuukan, habit). Sound hook: NAreru starts like NAtural, which is how a thing feels once you are used to it.