|Age||12 (main series)|
|Occupation||Violinist / Student|
|Japanese Voice||Terasaki Yuka|
Toshiya Mikke has brown hair and small brown eyes; he can often be seen wearing his school uniform. During the Gala concert he wears a formal white shirt and a black bow tie. He also wears slanted glasses.
Toshiya Miike has a tendency to get jealous easily, as shown in his contempt of Kaori Miyazono for stealing his limelight even though she lost to him at the Towa Music Competition. This can be seen again later on as he gets jealous of Kousei playing a duet with Nagi Aiza.
After hearing Kousei Arima play in the Gala concert, he begins to admire Kousei and even claims that Kousei is "The greatest pianist of all".
Even so, he is still prideful and is also very blunt, as seen in the coda, where he had no problems criticizing Erika Chadai whenever she made an error, and his anger stirs up whenever Nagi Aiza is praised over him.
Toshiya Miike is a talented violinist. He was the winner of the Towa Music Competition and was a winner of a middle school music competition. 
Miike first met Kousei at the Gala Concert where Kousei and Hiroko Seto requested for a change in the order of performance since Kaori hasn't arrived yet, in which Miike declined. He also insulted Kaori's way of playing the violin alongside saying that Kaori's music is disastrous and not a form of music or anything. Kousei apologizes for causing a disturbance, but vows to Miike that the spotlight will shine on Kousei and Kaori.
After Kousei's solo performance (since Kaori didn't show up), he saw Kousei on his knees backstage where Hiroko and Koharu Seto consoled him. Kousei's performance had an impact on Miike, making his form of playing softer than usual. He admired Kousei from then on.
He always gets fired up when Kousei will be involved in something where Miike is also involved. As seen in the coda, he was fired up when the third-year Nagi told him in the School Festival that her teacher, Kousei, is coming to watch.
Miike, as Nagi stated, hasn't said a word to her before. Miike asked Nagi why she played a duet with Kousei and also asked if she knew Kousei, making Nagi enraged. A fight almost ensued if not for Satsuki and Komugi holding back Nagi. He then asked if she knew Kousei's contact info and email address, in which Nagi said yes and that they ate taiyaki together, alongside saying that the taiyaki was delicious, in which Miike found himself at a loss. He shouted that Nagi knowing Kousei was unfair and ran away.
In the coda, Kurumigaoka Middle School was divided into two competing factions, with most of the male population favoring Nagi and most of the female population favoring Miike. They still fight and insult each other every time they meet, although Satsuki says that they're more like love rivals..
Miike is shown to be jealous of Kaori, since the audience is always fascinated by Kaori's performance. He always thinks her performance is not a form of music and insulted her before Kousei's and Kaori's performance at the Gala Concert.
- (To Arima Kousei) "Her kind of music is nothing."
- (To Aiza Nagi) "Why are you playing piano with Arima Kousei?!"
- (To 2 Strangers) "Oh, amateurs! The greatest pianist of all has yet to play, you know."
- (To Erika 'Chabo' Chadai) "If a performer...is blown away by another person's performance, it's a disgrace."