There comes a moment in every anime where even supporting characters are given an opportunity to shine. In Naruto, the Chunin Exam arc was not only centered on developing the main trio, but also introduced and developed numerous side characters, adding to the vast world-building that the franchise has excelled in.
During the exams, each character had a moment for them to reveal their jutsu, personality, and in some cases, their backstory, but in the case of Ino Yamanaka, her development leads to more questions. With just enough clues about her and mild details surrounding her family, a theory can be pieced together which explains the significant relationship Ino has with her hair and why cutting it during her match against Sakura was a bad idea.
Even before Sakura and Ino face off, their shared history is revealed when Sakura's life is in danger in the Forest of Death. Despite their contentious relationship, they were once best friends. Ino came to Sakura's rescue when she was being bullied in their Ninja Academy days and on top of protecting her from bullies, Ino also helped her build up confidence. Sadly, their friendship would fall apart once they learned they both developed a crush on Sasuke Uchiha. Though Sakura was the one to formally end their friendship and declared them to be rivals, Ino followed suit, giving Sakura the cold shoulder and even throwing insults her way.
As they graduated from the Ninja Academy, the two kunoichi grew out their hair after hearing that Sasuke is attracted to girls with long hair. From this point onward, their maintenance and care of their hairstyles become symbolic of their rivalry, as well as their infatuation with Sasuke. After learning more about the Yamanaka clan and clan tradition in Naruto, Ino's development becomes questionable.
The Style Of Tradition
Before delving into Ino's rash actions during her fight with Sakura, it's important to analyze the details of the Yamanaka clan and how Ino fits into her family. Early on in Naruto, there isn't much known about Ino's family, but across most, if not all, clans throughout the series are the shared ideals of tradition. One of the obvious traditions that can be easily seen across Clans is the shared sense of style among members.
Looking among the members of each clan, it becomes easy to tell who is a part of which family with their hairstyles alone. The Nara Clan members all have dark, spiky ponytails, while Huyga Clan members let their hair grow out and maintain a kempt style of their locks. Ino's family, the Yamanaka Clan, is no exception to this rule of a shared style of hair, among other similarities. In this family, the hair, which is most often some shade of blonde, is grown out and tied in a ponytail. Ino shares in her family's love of flowers and even at a young age appeared to watch over the family flower shop, so there doesn't seem to be any hints of rebelling against any traditions.
Perhaps it took some time for Ino to grow out her hair, which would explain why it was so short when she was little, and the traditional Yamanaka style could coincidentally match the rumored style of Sasuke's type. However, that still doesn't excuse Ino's brash decision to cut her hair during her fight with Sakura. Granted, it was a part of Ino's plan to distract her rival with the belief that she had lost her focus, and potentially her mind. By tossing her freshly cut ponytail at Sakura, with some hair strands making it to Sakura's feet, Ino laid down a trap that ensnared Sakura in a chakra-infused cord.
Moving forward with the series and paired with the fact that Ino does regrow her hair to match her father, the question remains whether there are any consequences of going against these cosmetic, surface-level traditions. It might depend on how strict the individual clan is, and since the Yamanaka clan is one of the biggest families in Konoha, there's a chance Ino might have had to give her father a proper explanation as to why she did what she did.
To be fair, Inoichi was rather passive and lenient when it came to his daughter, which might provide another explanation for Ino's short hair during her time at the Academy. However, as the daughter of the Head of the Yamanaka clan, Ino does have to firmly represent and uphold the values of her family. Her rude behavior toward her friends and the flippant way she is about her appearance goes against the values of her clan.
Representing The Yamanaka
With the symbol of the Clover Bush, the Yamanaka clan's values are rooted in the flower's deep meaning, which, in the language of flowers, translates to "positive love". Though her initial friendship with Sakura made her worthy of the Clover Bush symbol, Ino changed from a kind little girl into a jealous and crude young woman. It isn't until after her match with Sakura that Ino's kindness returns, but even then, and after a few years of growth, she continues to be overly critical of others and an incredibly shallow person.
When she finally outgrows her feelings for Sasuke and focuses on the Shinobi World War, Ino fully matures as a supportive and loving friend, albeit with a bit of tough love mixed in. Going back to her choice to cut her hair off during the Chunin Exam, it didn't have nearly the same emotional meaning as when Sakura did it. Although there was a practical reason for it at the time, the short bun that Ino wore represented how much more she had more growing to do in order to truly represent the Yamanaka clan.
Despite Ino being one of the less popular characters in the series, a number of fans have argued in defense of her very human flaws. The fact of the matter is that there's more to Ino than is shown in the anime. As a member of the Yamanaka Clan, there's a great deal of pressure placed on her shoulders, meaning that every mistake she makes comes with consequences. Though tactically, her moves during the Chunin Exam brawl with Sakura nearly assured her victory, she took on the challenge of her rival in a reckless way, with solid proof of her poor performance showing in her chopped-off ponytail.