しちまう

end up doing, go and do

→ 為る

し do + ちまう Completive aspect (often regretful)

verb · informal, present tense Rare #41,822

end up doing, go and do A very colloquial, often rough contraction of してしまう; it often suggests an unintended or regrettable result.

JA: また寝坊しちまう。

EN: I’ll end up oversleeping again.

Conjugation of 為る

Because of the commander, we're going to go bankrupt.

— エリート・スクワッド (2007)

I can't help getting frustrated.

— 最強のふたり (2011)

I'll freeze to death.

— 雪山の絆 (2023)