godan verb (-ru), intransitive verb
Physical entry into a place, often with a nuance of going where one is not supposed to be. Common in prohibitions such as 立ち入り禁止.
この先は危険ですので、立ち入らないでください。
Please do not enter beyond this point, as it is dangerous.
私有地に無断で立ち入ることはできません。
You cannot enter private property without permission.
godan verb (-ru), intransitive verb
Intruding into someone else's affairs, privacy, or personal matters. Often used with ことに or 問題に.
他人のプライバシーに立ち入るべきではない。
You should not pry into other people's privacy.
彼はいつも私の個人的な問題に立ち入ってくる。
He always interferes in my personal matters.
godan verb (-ru), intransitive verb
delve deeply; go into detail
Entering deeply into a topic, discussion, or investigation. Often used with 問題, 事情, or 細部.
この問題に深く立ち入る時間はない。
We don't have time to go deeply into this issue.
細かい点に立ち入って説明してください。
Please explain in detail, going into the finer points.