SakuIno

SakuIno is a Femslash ship between Ino Yamanaka and Sakura Haruno in the Naruto series.

Canon
Sakura and Ino were childhood friends. Ino approached Sakura because she was often bullied for having a large forehead and explained that hiding it with her bangs only made it worse. She then gave her a red ribbon so that she could pull her hair back. Sakura and Ino then became friends and often picked flowers together. When they were comparing themselves to flowers, Ino explained that Sakura was just a flower that had not bloomed yet but would be very pretty when she did.

Sakura and Ino eventually fell for Sasuke who was in their class at the ninja academy. Ino started to find her to be slightly annoying after learning this. Sakura eventually found out as well and decided that they had to be rivals before giving back her ribbon. After this point, they often exchanged insults such as 'billboard brow' and Ino-pig'. Sakura and Ino graduated at the same time and often fought over who got to sit next to Sasuke.

Sakura was placed on the same team as Sasuke which made Ino jealous. However, while in the Forest of Death, Ino saw Sakura being attacked by Sound Village Genin and decided to have her team protect her. After the fight, Ino helped Sakura cut her hair but was annoyed with the fact that she hugged Sasuke from behind. During the preliminary matches, they were forced to fight each other and it ended in a double knockout. However, they recognized each other as equals again because of this.

Sakura later went to the flower shop in order to buy flowers for Sasuke who was in the hospital and found Ino working there. She gave her advice but bought flowers as well. They arrived at the hospital and found that Sasuke was gone. They also decided to visit Lee together because they felt bad about his injuries. After Sasuke left the village, Sakura decided to train under Tsunade in order to become a medical ninja and Ino eventually joined in as well.

Over two years later, Sakura and Ino both took part in the Fourth Shinobi World War. They reassured each other multiple times on the battlefield. Two years after that, Sakura opened up a clinic and Ino eventually joined to help her. They were later on a mission and Ino was very upset with Sakura was captured but she eventually escaped. After the mission was over, Sakura encouraged Ino to go have lunch with Sai because she liked him.

Fanon
SakuIno is a very popular Naruto ship and is one of the most popular femslash ships in the fandom if not the most popular. It is supported due to their close childhood friendship as well as their rivalry that turned more friendly in nature as the series progressed. SakuIno rivals SasuSaku, NaruSaku, ShikaIno, and SaiIno.

Trivia

 * During their fight in the Chunin Exams, Ino is initially unable to go all out against Sakura until she proves her abilities.