Big Sister (ビッグ シスター) is the 2013 film directed by Hello! Project Co Producer Akami. The movie is based on deaths of little sisters and how they affect their big sister. The movie was cut into four parts. The three first parts are just smoothe and showing a big sister's grief over her sisters death (in which in the second one, the big sister commits suicide), while the fourth one is about how the big sister accidentally kills her sister and the younger one haunts her. Each opening for each part is the song from Morning Musume's 13th album, Be Alive.
In the first part, Muramoto Chie, portraying the character Nabe Ai, is shown visiting her younger sister, Miyamoto Karin (who portrays the character Nabe Haruko), in the hospital after it is revealed that she has cancer. One day, while visiting Haruko, Haruko tells her "Be an angel." and then dies. This leaves Ai to grief over her death. Two years later, it is revealed that Ai has lung cancer, due to smoking and drugs.
In the second part, Fukuda Kanon, portraying the character Akaike Miyo, is shown taking care of her younger sister, Tanabe Nanami (who portrays the character Akaike Kazumi), after their parents die. One day, coming home, Miyo sees that Kazumi has hung her self and sees a note from her saying:
"I can not stand it here. Our parents never deserved to die. I can't live in this cruel world anymore. Love you." One year later, after being in her foster parent's house, Miyo realizes the same thing that Kazumi did and drowns herself in the tub, leaving a note for the foster parent's saying:
In the third part, Kudo Haruka, portraying the character Tanaka Akira, is shown walking to school with her younger sister, Hamaura Ayame (who portrays the character Tanaka Masa). After Masa runs to pick up something she threw, she doesn't return. Akira waits about 15 minutes for her. Then, Akira starts to get worried, she runs to find her,and finds Masa dead on the ground. After, Akira blames herself about the death of her sister and orders herself to be arrested, but her Sensei (Tokunaga Chinami), talks her out of it.
In the fourth and last part, Xiao Miya, portraying the character Yamaguchi Rako and her younger sister Uemura Akari (who portrays the character Yamaguchi Rika) are on a boat together. After playing many games, Rako decides the rock the boat playfully. Her sister Rika, playfully begs her to stop and ends up falling out. Rako jumps in to save Rika, but it is too late. Rika drowns, leaving Rako to blame herself. But when asked about the crime, Rako lies about the death, saying that Rika went swimming in the lake and never returned, which made her feel even worse. Two weeks after the death, Rako stops grieving and Rika ends up hauting her. Rika tells her stop lying and just tell the truth. Rako denies it, but does tell the truth when Rika threatens to stab her.
- Miyamoto Karin (Part One)
- Tanabe Nanami (Part Two)
- Hamaura Ayano (Part Three)
- Uemura Akari (Part Four)
- Utsumi Kenichi (Foster Father, Part Two)
- Sudo Maasa (Foster Mother, Part Two)
- Tokunaga Chinami (Sensei, Part Three)
- Tanaka Reina (Police #1, Part Four)
- Saburo Eri (Police #2, Part Four)
- Wada Ayaka (Police #3, Part Four)