|Spoiler Alert: This article/section contains details about future plot lines described in the light novels, not covered in the anime. Do not proceed unless you want to be spoiled.|
|Novel Debut||Volume 11.5|
Tatsuo Itsuka (五河 竜雄, Itsuka Tatsuo?) is the father of Kotori and the foster father of Shido.
The father of Kotori and foster parent to Shido, Tatsuo is one of the employees in Asgard Electronics, <Ratatoskr>'s parent company. According to Kotori, he was part of the crew that helped create the Fraxinus and that he knows about the existence of Spirits, but doesn't know what they look like until the events of Itsuka Parents.
Tatsuo is described as a person who is always smiling under his dark green glasses and has a distinguishing hunchbacked posture.
Despite being a genius engineer, even his own wife admits that he is a little bit too naive and would have been scammed numerous times without her help. Despite this, Tatsuo remains a cheerful and upbeat individual, being willing to trust and befriend the Spirits despite their disastrous first encounter.
During his youth, Tatsuo was noted to be friends with Shinji Takamiya. One time a beautiful girl came to their class to deliver an item Shinji had forgotten, causing a huge uproar among him and his classmates. He eventually got married to Haruko Homura and had a daughter, Kotori.
Tatsuo and Haruko adopted Shido at a very earlier age after the boy was abandoned by his mother. Due to the nature of their work, both he and his wife had to relocate to the United States, leaving Shido in charge of the household chores in their Japanese home and looking after their daughter.
One day, Haruko and her husband suddenly made a surprise phone call to Shido while he was shopping for dinner ingredients. At first, they started off with a prank call, pretended that someone was kidnapped. However, after their disguise was seen through, they soon tell him without prior warning that they were already at the front entrance of their house. Thinking of the Spirits that are currently there, Shido made a desperate request for his parents to not enter the house. But since he was unable to properly explain why, his parents believed that he was merely hiding something naughty and proceeded to enter their domicile anyway with the mischievous promise to search through Shido's possessions meticulously. However, upon entering their house, the couple finds themselves ambushed by the Spirits, who thought that they were burglars. After the initial misunderstanding and some threats of torture from Origami, the Spirits quickly realize that they had accidentally traumatized Shido's foster parents. Afterwards, the Spirits planned a Japanese style welcoming for the Itsuka parents, as they feared that if their awful first encounter wasn't remedied, the parents would prevent them from seeing Shido again.
- Light Novel
- Volume 11.5
- Volume 18 (Flashback)