Got nervous by sitting close with 〜てしまう

Grammar Explanation: Doing completely or ending up doing with 〜てしまう and 〜ちゃう

Ayumu and Urushi head to the library so Urushi can help Ayumu study for an upcoming test. The library tables are filled with studying students, so Takeru offers to let the two join him and Sakurako at the library staff desk. Urushi sits beside Ayumu and explains the material as he works through it, but she stops to make sure he’s listening.

歩(あゆむ):: 「すみません」; “Sorry.”; 「いつもより距離(きょり)が近(ちか)くて緊張(きんちょう)してしまって…」; “You're a bit closer than usual, so I got nervous...”

Key Points

〜てしまって = ending up in that state
- 緊張(きんちょう)してしまって means Ayumu ended up getting nervous, not that he intentionally made himself nervous.
- The 〜てしまう pattern adds the sense that the reaction happened despite himself and is mildly awkward or unfortunate here.
Casual trailing て leaves the apology unfinished
- Ayumu trails off after 〜てしまって…, leaving the implied continuation unsaid, such as “that’s why I wasn’t responding well”.