BL Metamorphosis is the story of Urara and Yuki (Sunshine and Snow) who build a cross-generational friendship based on their mutual enjoyment of BL manga. Urara (Ashida Mana) is in her second to last year of high school and facing the choice of what college programs to apply for next year. She's working at a local bookstore when a recently widowed calligraphy teacher Yuki (Miyamoto Nobuko) wanders in to escape the summer heat and a finds a popular BL which catches her eye. Urara is an embarrassed secret fan of the genre, and Yuki had no idea such a thing existed but quickly finds that she loves it and seeks out Urara's advice to learn more about it and get her recommendations.

Acting is reacting, and, as ever, Ashida's reactions are on point, expressing all the embarrassment and social awkwardness of a young woman who has not found herself yet. Yes, she has a crush. But he's already dating the tall, popular, beautiful Eri, and what would happen if he or, worse, THEY ever found out she's into BL? Nevertheless, Urara guides Yuki into the world of BL fandom, and Yuki encourages Urara to try making a manga of her own.

The film is quite smart with lovely parallels drawn between the manga that the two are reading, and the other things happening in their lives. The score and song choices help to propel the story along and as whole the film feels much shorter than its two hour runtime.

It is, indeed, rare for a film to center on a friendship between two people with an age difference of over 60 years, and this film does so lovingly and well. Ashida, if she chooses to, will be Japan's breakout star in the coming years and Miyamoto is a good solid veteran actor. Together their scene work provides all the warm-fuzzies you could want.