I haven't seen Sm:)e but the description sounds similar to I'm Not a Robot which is about a cynical man who has a condition where he is severely allergic to other people.

Both have a similar plot where the death of someone close to them causes the main characters to seek revenge. As the story progresses, the characters begin to learn more about the past and the events behind their loved one's death, and the only people they can trust are each other.

'The Twilight Samurai' has a much more more quiet and sombre mood in comparison to 'Kakekomi,' which although has a similar aesthetic, is also light-hearted at times. Both films are set in the edo-period, and present men and women in an exceptionally interesting way, considering how most Japanese films portray and convey ideas in regards to gender roles (though Twilight Samurai is more subtle in this). 'The Twilight Samurai' is probably still a bit on the traditional side.

Both films concern the topic of Korean comfort women in the second World War, although 'I Can Speak' also includes issues such as the treatment of the elderly in Korea.
The majority of the film time in 'Spirits' Homecoming' is set in the historical period and focuses primarily on the experiences of Korean comfort women in WW2. 'I Can Speak' on the other-hand is set in the present time and is therefore more concentrated on remembering and learning from the past events.
The genres of both films are also quite different. If you're up for something more lighthearted, 'I Can Speak' is the way to go. If not, just a warning...'Spirits' Homecoming' may be a little disturbing for some viewers as the raping scenes are quite violent and explicit (no full nudity shown however), and there are other violent scenes with killings and fighting.