|Name: Tarou Mitsuki (海月 太郎 Mitsuki Tarō)|
|Hair Color: Dark Brown|
|Eye Color: Dark Red|
Blood Type: A
|Talent: Piano Playing|
|Favorite Subject: Music|
|Favorite Color: Brownish Red|
|Favorite Type of Girls: Low Maintenance Girls|
|Hopes to Go: Germany|
|Enemies: Gaito, Sara (former)|
|Love Interests: Sara and Hanon Hôshô|
|Voice Actor: Daisuke Kishio|
|Position in the Series: Supporting Character|
Tarou has dark brown hair, brown eyes and he usually wears a beige suit and tie. In his memories with Sara, he wore a light green t-shirt and blue jeans. During his piano recitals, he wears a black tux and somewhere hidden in his jacket pocket, he'd have his half of the oyster shell which symbolizes his relationship/love with Sara.
Tarō is a kind-hearted man who deeply cares for his music. While he looks happy and pleasant on the outside, he has a deep secret involving his knowledge about mermaids. The memories of his relationship with Sara always come to his head whenever he is playing the piano, though depending on how he is feeling, he can make the song very relaxing or sad sounding. Tarō probably thinks about Sara all the time, since the piano song he wrote was originally dedicated to Sara.
Despite his feelings for Sara, there is a possibility that Tarō may had also had feelings for Hanon Hôshô as well. Proof would be whenever Hanon links her arm around his arm, he never seems to be bothered by this action and he also blushed in front of Hanon in Episode 22. Another obvious proof was before his departure to Germany in Episode 55, he spent the whole night before writing a piano piece and kissed Hanon's forehead before leaving.
Tarō was the music teacher at the school that Lucia Nanami, Hanon Hôshô and Rina Tôin attended who once had a relationship with Sara years ago, but he left. Later on, Tarō revealed why he left Sara because she was the orange pearl princess that she had a lot of responsibilities and he wrote a love letter to Hanon Hôshô in Episode 83.
- Since Tarō is rather young, he easily got along with Hanon Hôshô and the other students.
- Hanon sometimes calls him "Tarou-chan" or "Mitsuki-sensei".