First Love (2000)

This coming-of-age story from Japan opens just after 17-year-old Sataka has gotten dumped by her boyfriend. When her mother is hospitalized with a malignant stomach ulcer, Sataka is left alone with her emotionally repressed father; whiling away the hours one day, she comes across a love letter written to her mother 24 years earlier. Deciding to track down the letter's author, Sataka eventually finds Shinichiro (Hiroyuki Sanada), an overweight slob who was abandoned by his wife years earlier and now spends his time hanging around pachinko parlors. Determined to clean him up and reintroduce him to her mother, Sataka nags Shinchiro until he finally agrees to her demands, and a gradual friendship develops between the two as Sataka drags him to the gym and a clothing store. But once Shinchiro's makeover is complete, he turns the tables on his young friend, and when the time comes for him to meet Sataka's mother, all concerned parties find themselves embarking on a new phase in their lives.

Unfortunately the movie First Love is not yet available on HBO Max.