Recommendations

School boys in blue shorts fighting the good fight to survive high school, family, friends and stay true to themselves.

LoS has more family dynamics.

LS:TS has more friendship/love dynamics.

ok, it's not a direct recommendation, the movies differ, notably in the case of music - Fish Story is about music, See You is definitely not. But there are some links: time span, Hamada's similar role, general climax, different stories involved.

Rurouni Kenshin: Kyoto Inferno (kyoto Taika hen) is the sequel to Rurouni Kenshin. It features the main characters and introduces Battousai's successor Shishio who tries to take over Japan. Can Kenshin beat Shishio while keeping Battousai at bay?

both are about women who come from the future to help themselves in the present

the same main female actress
both are about women who are betrayed by their husband

the drama narrates the story of a touching friends between two friends with a twisted and cruel fate

Both are boy meets boy coming of age story in high school setting.

MB may leave you teary-eyed.
LS may leave you hopeful.

Kekkon Dekinai Otoko is the original Japanese version of The Man Who Can't Get Married. If you enjoyed one, you will probably enjoy the other!

Both are slow starters with well-crafted stories and secret gold stash in the crux of their mysteries.

The same female actress in main role (she improved her skills);
similar plot (even better, more interesting characters and twists ) ; OST really good in both of them; fighting scenes; funny moments; Adjumma (you'll see if you watch it ;D);

The movie is about a father who dies but then gets another chance to bond with his son. He becomes a high schooler and tries to become his son's best friend. HILARIOUS!

Over the Rainbow is also about young people trying to survive in the music industry. It's a bit darker and more serious than Goo Hae Ra.

Another Hyun Bin drama in which the main characters change souls. So you get to see him acting like a woman! xD

This movie is not about a split personality, but it's about a father who died and bargained with an angel for a deal. He was sent back on earth as his son's new friend. Touching and hilarious at the same time!

Both dramas deal with similar issues, about finding who you really are and what you want to do with life. Both have music as the main theme.