Akatsuki Suppression Mission
Since as a child, Ino has maintained a mild crush on Sasuke Uchiha. Upon meeting Sai, she quickly became interested in him, also noting that he resembled Sasuke.
When Team10 (without Shikamaru) and Team 7 all went out to dinner, Ino attempted to get Sai's attention with some subtle flirting. When Sai tried to befriend Ino and Chouji, having earlier come to the conclusion that women (specifically Sakura), didn't like to hear how they really looked, Sai tried the opposite approach by calling Ino gorgeous. Ino blushed, even though she had no idea that Sai was actually calling her ugly like he had with Sakura.
Birth of the Ten-Tails' Jinchūriki Arc
Kaguya Ōtsutsuki Strikes Arc
Later, Sai, Ino and everyone else are released by Naruto and Sasuke from the Infinite Tsukuyomi.
Blank Period Arc
Shikamaru Hiden: A Cloud Drifting in Silent Darkness
Ino, along with Chouji and Temari, come to the rescue of Sai and Shikamaru after they were captured by a man named Gengo. Placed in a powerful genjutsu, Ino uses her Mind Body Switch Technique to help free Sai. Sai thanks Ino and they share a heartfelt smile.
Sakura Hiden: Thoughts of Love, Riding Upon a Spring Breeze
Sakura learns that Ino likes Sai, but doesn't know how to express herself to him.
The Last: Naruto the Movie
In the ending credit, Sai and Ino attend Naruto and Hinata's wedding. They can be seen standing next to each other and holding hands together, hinting they are in a relationship.
Years later, Sai and Ino is revealed to have a son named Inojin Yamanaka. Sai, Ino, Chouji and Karui are seen waiting for their children. Seeing how angry Ino is, Inojin is seen hiding behind a tree saying that he can not come out without Shikadai and Chōchō.
- Ino was shown attracted to Sai during their first meeting.
- Despite Ino knowing Sai mentally called her ugly during their first meeting, Ino was still shown to hang around him.
- During the Infinite Tsukuyomi, Ino was shown dreaming of Sai being one of the two characters fighting over her.
- It is revealed in the final chapter that Sai and Ino are married and have a son named Inojin Yamanaka.
Among the Fans
Although SaiIno isn't very popular in the fandom, it is well known by the fans. Although the popularity has dropped due to the characters no longer seeming to interact, the couple's fanbase significantly grew once again when it was revealed that Ino and Sai eventually had a child and got married. Many members of the fandom call this pairing the flower and the root. It is sometimes a companion couple of ShikaTema and is a rival couple of ShikaIno and SaiSaku.