|Japanese Name||音無 伊御|
|Romanized Name||Otonashi Io|
|English Name||Io Otonashi|
Io has dark hair with an ahoge, along with black eyes and glasses. Like most of the students of Nekoge Prefectural High School, he is mostly seen in his school uniform, although he has been shown in other outfits as well.
He is smart and stoic, yet kind at heart. He is responsible and independent. He is oblivious to Tsumiki's crush on him, though he sometimes makes romantic comments/gestures towards her. She is the closest girl to him regardless. Like Tsumiki, he is a good cook and is considered a genius. Io is naturally calm, but he apparently detests laziness or slacking in general, as he hit Mayoi on the head once when she became distracted from her studies.
He is usually seen in school spinning a pen with his hand, fast enough to catch Mayoi's surprise at the speed. Pen-spinning seemed to be a hobby, since Io is very often seen doing it in the anime, also spinning some other objects like chopsticks and fireworks. At times, he unknowingly acts like a casanova, and thus is very popular with cats. His popularity with cats may have been a nod to Tsumiki's more-than-obvious crush and reactions when close to him.
Io is emotionally dense, as he often fails to recognize Tsumiki's romantic attractions towards him and is unaware of the fact that his charm made him so popular with animals (specifically cats), claiming that his peaceful disposition made them happy instead.
He is also quite strong, though not shown as often as Tsumiki, as shown during Sakaki or Mayoi's pranks and antics.
In the manga, he is able to catch a fish with chopsticks, while in the anime, he is able to kill a mosquito with a toothpick. He also displays a lot more expressions and emotions than he did in the anime, as he seemed to panic when Tsumiki bit him on the head and was nervous when the girls (Hime non-inclusive) discovered his part-time job at Hatch Potch.
- Tsumiki Miniwa - Io is the target of Tsumiki's intense crush, though he almost always fails to see the signs, even when Mayoi teases both of them about it. Despite this, Io's attitude and disposition towards Tsumiki was a lot friendlier than towards other characters. Io thinks Tsumiki is cute, and would often give her a pat on the head from time to time in the anime.
- Mayoi Katase - Mayoi is one of Io's classmates, who likes to tease him and Tsumiki about the latter's crush on him. Unlike Tsumiki, who goes ballistics upon hearing the teases, Io remains calm and friendly towards Mayoi, despite disapproving of her antics. Io hit Mayoi once in the anime because she was lazing out, this is the first time Io was seen hitting someone else.
- Hime Haruno - Io's charming and stoic expressions often leads to Hime (and occasionally, Tsumiki) blacking out due to excessive nosebleeding. Hime is Io's co-worker at Hatch Potch cafe before Mayoi and Tsumiki discovered the shop. He apparently considers her a close friend, as he entrusted his part-time job secret to her (which she later failed to keep) and was also seen acting friendly towards her when she is hurt.
- Sakaki Inui - Sakaki is Io's best friend, and is almost always seen hanging out with each other. There seemed to be some sort of a rivalry between the two when it comes to video games and sports, as Sakaki always strives to beat Io and are highly disappointed when he fails to do that. He occasionally goes to the arcade with Io after school and was aware of Io's part-time job (as Hatch Potch was owned by his sister Miiko).
Also look in the Io image section.
- In episode 5, his standing hair spins due to excitement of the bet (Pork sandwiches and Fried noodle bread).
- Io is extremely attractive to cats. Cats hoard around him, catch toys for him, and follow him around.
- According to Sakaki, Io’s weakness is Miiko, specifically when she asks him to do things for her.
|Tsumiki Miniwa - Io Otonashi - Mayoi Katase - Hime Haruno - Sakaki Inui|
|Saki Sakimori - Ami Kirino - Kikue Sakuragawa - Kyōya Saibara - Miiko Inui - Kana Miyama|