stuck on

Adjective

idiomatic not-comparable of a person slang of a thing usually of a problem

Japanese Meaning

（人物について）心から魅せられ、恋に落ちている状態。 / （事物などについて）非常に魅力的に感じ、夢中になっている状態。

He's been stuck on his classmate since the first day of school, always finding excuses to sit nearby.

彼は入学初日からクラスメートに夢中になっており、いつもそばに座るための口実を見つけている。

Sense（1）

(slang, idiomatic, of a person) Infatuated with; romantically attracted to; in love with.

Sense（2）

(idiomatic, of a thing, fact, etc.) Fascinated by; enchanted by.

"I'm stuck on the way you sing that Grieg song," he declared.

Sense（3）

(idiomatic, of a problem, thing, or situation) Puzzled or stumped by.

"I'm doing today's crossword puzzle, and I'm stuck on this one clue."