Takeshi (Takashi Tsukamoto), an Italian restaurant chef, and Ruri (Saki Aibu) could have been lovers, but Takeshi was too comfortable with their current relationship that he chose to stay best friends with her. Now, Ruri is engaged to another man and Takeshi is deep in regret. He runs through the night of Tokyo to tell her his true feelings before it’s too late, but right as he stands in front of Ruri, an unfortunate accident takes his life away. However, a twist of fate brings them back together once again in an ironic situation. "Eternal First Love" unfolds as a bittersweet story of an everlasting "first love."
| Actor | Role |
|---|---|
 Saki AibuRuri Sato | Ruri Sato |
 EXILE MAKIDAIYuki Makihara | Yuki Makihara |
 Takashi TsukamotoTakeshi Tanaka | Takeshi Tanaka |
 Tomohiro IchikawaToshifumi Makibara | Toshifumi Makibara |
 Ennosuke IchikawaKoji Mizusawa | Koji Mizusawa |
| TTomoki OkayamaTakeshi Tanaka | Takeshi Tanaka |
| KKen MogiDoctor | Doctor |
 Tsubasa MakotoHitoko Makibara | Hitoko Makibara |
 Kinya KitaojiYuichi Makibara | Yuichi Makibara |
 Natsuko KobayashiNot listed | Not listed |