Everybody remembers being bullied at school, but nobody remembers being a bully. That maxim occurred to me during this stark, sober, flawed movie with which Jessica Hynes makes her worthwhile debut as writer-director. It feels like a very personal film, well acted by the A-list cast that Hynes has assembled: a cathartic meditation on the need to heal, the need to confront those who do wrong and to confront yourself when you’ve done wrong.

Hynes stars as Tina, a care-home nurse with an unhappy relationship with her elderly parents, strongly and sympathetically played by Anita Dobson and Christopher Fairbank; Shaun Parkes gives a warm and likable performance as Tina’s partner, Mick. Their sensitive daughter Emma (Sennia Nanua) is being bullied at school by a girl called Jordan (Liv Hill), whose apparently charmless, hardbitten mum Amanda (Rhona Mitra) knew Tina when they were teenagers back in the day and now seems intent on pursuing a nasty like-mother-like-daughter vendetta against her outside the school gates.

Yet things are more complex than they at first appear. Tina knows she has to face up to them. And how does she do this? By taking up boxing. The fierce coach (Cathy Tyson) gets her to toughen up, and Hynes gets a Rocky-style training montage. But is boxing the right answer for Tina, literally or metaphorically? When Tina talks about her emotional and family problems, Mick replies: “Boxing’s not going to help with that …”

It’s a fair point. Is the cultivation of focused aggression and violence really going to tackle the complex problems here? I’m not entirely sure. But Hynes is very good in her boxing scenes. She looks convincing as someone getting better in the ring and happier and more confident outside it. She is such a strong screen presence.