Kokoro, by Natsume Soseki (paragraph #969)

無經驗な私は氣味を惡がりながらも、にや/\してゐた。

translation

Inexperienced, I grinned even though I was feeling creeped out.

kanji (pronunciations & definitions)
: I (わたし), me, I (あたくし), I (あたし), I (アタシ) : evil (あく), wickedness, (role of) the villain (in theatre, etc.), the bad guy

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