While very different in genre and tone, both Signal and Tokyo Girl tell stories of people using a device to communicate with someone in the past, so the characters build up their relationship/friendship despite not being together in person.

The series Signal is about a police profiler in 2016 who finds an old walkie-talkie that he uses to communicate with a detective in the 80's, while the film Tokyo Girl is about a girl in 2008 whose phone ends up with a boy in 1912. Both stories involve the two main characters not meeting for the majority of the story, or not at all.

Again, they are from two different genres, so it's not so much that you'll like one because you like the other. It's just that they share this common theme that you might want to see in something else.

Both films are, in their own ways, about one person trying to learn about the life of another person, who they previously did not know everything about. Both films handle this by showing us our main guy, in present day, meeting people and learning about the person through stories, and then, we, the audience, are shown flashbacks where we too learn about the life of the person.
Memories of Matsuko is about a young man piecing together the life of his now deceased aunt, who he didn't even know about beforehand, while The World of Kanako is about a father whose daughter goes missing, and as he doesn't have a close relationship with her, he learns about her from others and has to piece together her life in order to track where she's gone.

Both films are quite dark (World of Kanako is more unsettling and graphic while Memories of Matsuko is more tragic and depressing). If you've seen The World of Kanako, you can handle Memories of Matsuko, but if you're coming from Memories of Matsuko, please be aware that The World of Kanako is a lot more graphic.