接続・逆接N2
〜つつ（も）
while doing... / although... (still)...
Structure
V-ます形（語幹）+ つつ（も）
Explanation
① つつ means "while doing", more literary than ながら; ② つつ(も) is concessive ("although... still..."), with the main clause going against one's will. Attached to the masu-stem of verbs.
Examples
音楽を聞きつつ、本を読んでいる。
I'm reading a book while listening to music.
ダイエットをすると言いつつも、つい甘いものを食べてしまう。
Although I say I'm going on a diet, I can't help eating sweets.
Note
つつ is like ながら but more literary. The concessive つつも is a frequent N2 test point.