Verb (plain form) + 上は

[Now that / Since]

Connection: Verb (plain form) + 上は

Usage: Expresses that once a decision has been made or a situation has come about, one must follow through with the appropriate action. Implies a sense of determination or obligation. Often used with expressions of resolve like 〜なければならない, 〜つもりだ, 〜べきだ.

Similar expressions:

• 以上（は） = very similar meaning, slightly more common
• からには = similar, emphasizes resolve

Examples:

引き受けた上は、最後まで責任を持ってやります。(Now that I've taken it on, I will see it through to the end with responsibility.)

日本に留学する上は、日本語をしっかり勉強するつもりだ。(Since I'm going to study abroad in Japan, I intend to study Japanese thoroughly.)

やると決めた上は、途中であきらめるわけにはいかない。(Now that I've decided to do it, I can't give up halfway.)