I-Pin is an assassin from Hong Kong. Even though the 5-year-old I-Pin cannot speak Japanese well, the 15-year-old "Adult I-Pin" eventually enters a Japanese college, and despite the fact that she is the 3rd Most Promising Young Assassin (Fuuta ranked her as being the third out of 52,262 people for being a Promising Assassin), she works part-time at a Chinese restaurant in the future, though she still retains her skills. Kawahira is a frequent customer of the Chinese Ramen Shop that the 15-year-old I-Pin works for; however, it seems that every time I-Pin goes to deliver the ramen, she is transported into the past by the Ten-Year Bazooka, and the noodles become soggy. When she is first seen, it is believed that she is a boy due to her unfeminine apperance. She would often beat up Lambo because she sees him as a "Broccoli Monster" due to her near-sightedness. She has a crush on Kyoya Hibari, who looks like her master Fon, and every time she sees him, she gets shy and activates the Pinzu-Timed Super Explosion.
I-Pin is first seen being whispered to by Reborn. However, when Birds commands Jiji and Djidji to attack Haru, Her Future Self is revealed to have been protecting Haru and Kyoko, but is then switched with her 5-year-old self, when the later is shot by the Ten-Year Bazooka.
I-Pin, Fuuta, and Lambo are attacked by Leviathan's subordinates. After Lambo is hit, I-Pin does battle with one of the thugs to protect them. When Tsuna shows up, it is revealed that even this young I-Pin successfully held her own against a Varia member.
Arrival & Search for the Strongest
Future I-Pin and Future Lambo are seen briefly for this period; they are being attacked by Nosaru and Tazaru while trying to lead Haru and Kyoko to safety by means of Lambo's entrance to the hideout. Before Adult Yamamoto has a chance to finish Nosaru off, he reverts to his regular self and she, Yamamoto, Haru, and Lambo (all from the past) are knocked unconscious.
Ryohei later gives her a doll of her master Fon, which is shown to have a Red Arcobaleno Pacifier.
While everyone was training for the Choice battle, Chrome wasn't eating properly and not joining the others. One day, I-Pin went to her room and offered her a gyoza bun. Both of them sat in the room and ate together. After that, Chrome was starting to open up to the other girls (Bianchi, Kyoko, and Haru), and they all became somewhat of friends.
I-Pin is not one of the participants in Choice and therefore watches the battle from the Vongola viewing area.
- Excels in Martial Arts.
- Gyoza-Kempo/Fist - Combining her martial arts abilities with special Gyoza dumplings laced with the scent of garlic. This technique sends a wave of garlic striaght to the enemy's brain, and numbs the brain, which makes the muscles of the enemy move involuntarily. Since no one senses the garlic people believe that I-Pin is using psychic abilities.
- Each of her gyoza contain the essence of 5 million normal gyoza, and as such if they are eaten by anyone not trained in the Gyoza-Kempo/Fist, the person will die. This was shown to nearly happen with Kyoko and Haru. Luckily, I-Pin's master has an antidote.
- Pinzu-Timed Super Explosion - I-Pin's most destructive ability, activated when she is extremely shy (like with Hibari) or extremely mad (like with Lambo), a special countdown begins and appears on the middle of her forehead. The numbers come from the Mahjong tile pieces. When the countdown gets to 1, she will start to glow and then become a human bomb. She likes to hold onto someone when she explodes. Her explosion can create a small crater with its destruction. She is unharmed by her own explosion. Adult I-Pin had this ability sealed away by Fon, but it is later reactivated with the password "Broccoli Monster".
- Haisangen (Adult I-Pin) - A move only Adult I-Pin uses, she lays on the enemy's shoulders while they are standing, locking their arms and head. Then she breaks both arms and neck. She has only done this move on a non-human looking character.
- "Broccoli Monster" is the password to unlocking Adult I-Pin's Pinzu-Timed Super Explosion.
- In the Reborn! Fandom, her shorthand can be either I or Pin.
- Her master is the Storm Arcobaleno, Fon, and she fell for Hibari who suspiciously looks similiar to her master. She had such a crush on him that she made chocolates for him on Valentine's Day.
- Her first Japanese word was "Delicious", which was said to Chrome about I-Pin's special buns that seemed to cause erratic movement (in manga only).
- In the Future, she seems to be over her crush on Hibari.
- Due to her single braid. she is called "Tail Head" by Lambo.
- I-Pin's name is a refererence to the Mahjong Pinzu tiles.