Hanatarō states, when he introduces himself, that his name is relatively easy to remember, though Ichigo says otherwise, stating that if his name was Hanako (a girl's name) or Tarō (a boy's name) it would be easy.
The name Hanatarō, according to Ichigo, is just confusing. Hanatarō taken hostage by Ichigo and Ganju. Hanatarō first arrives alongside his division to assist in medical relief. He loses track of them and when attempting to ask some members of the 11th Division where his division has gone, he trips into them and causes them to fall down, in turn he inadvertently meets Ichigo Kurosaki and Ganju Shiba. Much to his dismay they devise a plan to get themselves away from the 11th Division by taking him as a hostage. The 11th Division members simply look on in confusion causing Ichigo and Ganju confusion as well, until Hanatarō explains that he is of the 4th Division while the others are of the 11th Division. The 11th Division members further explain that they are the strongest of the Gotei 13, while the 4th is so weak that all they are good for is medical operations. They are also the division that the 11th Division dislikes the most, therefore they insist Ichigo and Ganju kill him. Feeling bad about the situation the two resolve to simply fight their way out of the situation instead of going along with their original plan of taking Hanatarō hostage.
Thanks to a large explosion Ichigo and Ganju decide to take cover while accidentally taking Hanatarō with them. Hanatarō introduces himself when they find a place to hide. When Ichigo and Ganju use their map to determine the best route to Rukia they decide to leave Hanatarō behind as he is no use to them until he reveals that he knows the location of Rukia Kuchiki. Hanatarō converses with Ichigo and Ganju in the sewers. Hanatarō takes Ichigo and Ganju through the sewers as a shortcut to get to Rukia's prison cell.