Mami (Mugi Kadowaki) is a ‘hikikomori’, a withdrawn shut-in who struggles to relate to the outside world and spends most of her time holed up in her bedroom reading manga and refusing to engage with other people. Her supportive but frustrated father finds her a day job testing videogames. Once she is there, a production manager discovers her apparent talent for illustration and hires her to become the company’s next character designer. Mami only knows how to copy other people’s art; can she find her own originality?

Her Sketchbook is a pleasant but relatively ordinary romantic drama from writer/director Masaya Ozaki. In terms of film-making technique it weirdly feels about two decades out of date, with cinematography, editing and particularly music that would not feel out of place in the late 1990s. There is nothing that the film does that feels particularly sub-standard, but neither does it accomplish anything out of the ordinary. It’s a very watchable melodrama for fans of Japanese cinema and culture.

It is at the culture end that the film is the most interesting. Hikikomori – a word literally meaning ‘pulling inward’ or ‘being confined’ – refers to a Japanese phenomenon that has developed over the past two generations where individuals isolate themselves in their homes and shun any significant social contact (and in some cases all social contact). They often start as high school dropouts, but some become trapped in the lifestyle for decades. A 2010 Japanese government study estimated as many as 700,000 hikikomori lived in the country, with an average age of 31.

Mami is an easy character to like, because while she struggles terribly with social situations she continues to put effort into it anyway. Mugi Kadowaki does a great job with a difficult role: Mami struggles to express herself and her emotions, so how then to express them to the audience? It’s a wonderful subtle and gently powerful performance. The supporting cast are all solid, but no individual really stands out from the crowd.

It is worth commending the film for not taking all of the obvious story choices. At the outset it sets itself up as something of a romantic comedy. It isn’t. Later events also bring a personal conflict to head when Mami accuses someone of trying to ruin her new-found career; it turns out they are completely innocent, and justifiably offended.

Her Sketchbook comes with an admittedly mild recommendation. The subject matter of Japanese shut-ins gives it plenty to work with dramatically, and the videogames industry setting gives it a little bit of background texture, but altogether it is simply a pretty ordinary drama. There are much better things to spend time watching, and more valuable motion pictures to hunt down. It’s rather charming, fairly inoffensive, but ultimately it’s simply just there.