Is Kono Sekai no Tanoshimikata: Secret Story Film hentai?
No
Rated PG-13 (Teens 13 or older) on MyAnimeList and not tagged as Hentai.

Movie · 2020 · 1 episodes · PG-13 - Teens 13 or older
Idols (Male), Music
An anime movie based on HoneyWorks' LIPxLIP virtual idol unit, commemorating the music circle's 10th anniversary. (Source: MAL News)
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