For the specific "WEBRip" release you mentioned, subtitle files (.srt) are often hosted on community databases. Note that these are unofficial and may vary in translation quality: Film Review: My Broken Mariko (2022) by Yuki Tanada - IMDb
The story follows Tomoyo Shiino, an office worker who discovers her best friend, Mariko, has committed suicide. In a final act of devotion, Tomoyo steals Mariko's ashes from her abusive family to take her on one last journey to the sea—a trip they never got to take together while Mariko was alive. subtitle My.Broken.Mariko.2022.JAPANESE.WEBRip....
Available for purchase or rent in certain territories. Community & External Subtitle Files For the specific "WEBRip" release you mentioned, subtitle