Koe no Katachi, 3-gatsu no Lion Recommendations
Both of these look heavily into self-loathing and self-discovery. They are, at their cores, stories about forgiving yourself and overcoming your own psychological weaknesses. They are about discovering what it is that you want to do in life and what your passions mean. Fantastic directing, art, animation, and style in both. Some of the best at setting a deeply reflective mood. Tons of good drama and character building as well.
Deals with a depressed kid and really conveys the emotion fantastically
Both are heartfelt dramas that deal with depression, isolation, and the human condition. They both teeter between heavy and uplifting atmospheres and give off a similar vibe. Season 2 of 3-gatsu also touches upon bullying in a similarly beautiful manner as A Silent Voice does.
If you liked A Silent Voice, you'll probably enjoy 3-gatsu and vice versa.
Both are very personal drama's, that give the viewer credit to infer and which focus on the protagonists emotional turmoil. There isn't a shred of doubt in my mind that 3-gatsu no Lion is the most similar anime to Koe no Katachi in existence. Trust me, I've seen everything considered even remotely similar.
Koe no Katachi - Definitely watch it subbed
3-gatsu no Lion - Preferably watch it dubbed
Both of these animes deal with the consequences of depression and, while to a much less pronounced extent with 3-gatsu no Lion, bullying and feelings of inadequacy. The primary driver in both of these stories is character interaction, which both helps and hurts the MCs.
A high school student suffering from depression and loneliness has to face his past-self and grow as a person. Both of these are touching anime and if you enjoyed 3-gutsu no lion you're sure to enjoy Koe no Katachi
Wow, Rei, Kousei and Shouya, nothing more to say about this 3. Struggling with their pasts, feeling guilty, everybody'd love to see their journey to find their true selves and seek for salvation.