いっせん
Issen
一線 (Issen) is a Japanese noun meaning “one line, (a) single line, boundary, line (between things)”.
Meanings
- nounone line; (a) single line
- nounboundary; line (between things); distinction
- nounforefront; front line
Examples
彼は愛想のいい奴だが気軽に踏み込ませない一線を持っていた。
He was an amiable fellow, but had a certain reserve that he would not let you casually trespass upon.
Sentences from Tatoeba (CC BY 2.0 FR).