なってしまう

end up becoming

→ 成る

phrase Rare #28,598

end up becoming Often suggests that the change is unintended or regrettable. In some contexts, it can mean that you can't help becoming a certain way.

JA: 彼のことを考えると、心配になってしまう。

EN: When I think about him, I can't help getting worried.

寂しくなってしまうわ

I end up feeling lonely.

— どん底作家の人生に幸あれ! (2019)

あの子は一体どうなってしまうのかしら。

I wonder what will become of that child.

つまり―ここでは水が突然なくなってしまう

In other words—this is where the water suddenly disappears.

— イル・ポスティーノ (1994)

最もすばらしい食事もブタにやる残飯のようになってしまう。

Even the finest meal becomes nothing more than scraps fed to pigs.

このままではハウルは荒地の魔女のようになってしまう

At this rate, Howl will end up like the Witch of the Waste.

— ハウルの動く城 (2004)