Kosuke is a handsome man with medium-length blonde hair, gold eyes and he wears earrings and a chain necklace.
He is usually wearing his lab coat with a FC Inter shirt & kit with number 13.
Kosuke is a big otaku who loves 2D girls where is so in love with his 2D girls that he sleeps with body pillows of them and invests large amount of money on their games. He knows that other people would find his preferences weird, so he usually hides them and plays a ladies man, who's been in love with lots of women. Usually when he tells a love story or something he did with a girl, it's from the dating sim games he is playing. Even though he no longer plays soccer, he still loves wearing their T-shirts.
Kosuke came to the Saitama University after been absent from some time, commenting he was enjoying the night life. Shinya Yukimura asked him if he had loved someone and Kosuke replied he lives in love. He then explained about the girl he loves and gave Shinya the proofs he wanted for his love to her, like being happy around her, sleep-hugging her for 2 years, spending lots of money on her. But then Kotonoha Kanade revealed who Aika (Kosuke's love) was, a character from a dating sim game. Kosuke then confessed he was in love with 2D characters and he was hiding it because people find it weird and they would make fun of him. Shinya then gave him a speech that his love isn't weird, as they are different sexual orientations and that loving 2D girls is similar to loving celebrities. Kosuke was moved that Shinya accepted him immediately and decided to continue his love to 2D girls. But then Ayame Himuro said that Kosuke's love to Aika and it can't be compared in numerical values to Ayame's love to Shinya and that would mean she didn't love Shinya, he instantly took what he said to Kosuke and told him he is extremely weird for sleeping with body pillows of characters, leaving Kosuke shocked.
- The name Kosuke means "tiger" (虎) (ko) and "help" (輔) (suke).
- Kosuke's surname Inukai means "dog" (犬) (inu) and "rearing" (飼) (kai).
- The main protagonist of Mobile Suit Gundam 00F, Fon Spaak heavily resembles Kosuke.