| Relationships |
Saegusa Mayumi[]
Hattori shows great respect towards Mayumi, at times going as far as to show affection towards her.[1] He has been frequently bewitched by her beauty and antiques. However, he is usually just a victim to Mayumi's teasing.[2] For instance, he was forced to eat a Valentines day chocolate which was extremely bitter as a warning and prelude for Tatsuya on what is going to happen to him next.
In May 2099, it is revealed Hattori has still not gotten over his feelings for Mayumi when it is revealed by his cousin that he has maintained his unrequited love for her since High School.[3]
Ichihara Suzune[]
She picked him with Kirihara Takeaki as bodyguards during the AD 2095 Thesis Competition.[4] She also allowed him to accompany her when visiting Hirakawa Chiaki during her hospital stay, showing a great deal of trust.[5]
Shiba Tatsuya[]
Hattori initially had an antagonistic view on Tatsuya and his status as a Course 2 student.[6] Even after being defeated fairly in their duel, he did not speak to Tatsuya and mostly resorted to simply ignoring him.[7] However, it is apparent that Hattori does in fact acknowledge Tatsuya's skills, as he supports Tatsuya's acceptance as CAD Engineer for the Nine Schools Competition, juxtaposing to his earlier attitude towards him.[8]
In Volume 10, Hattori had asked Tatsuya for water after falling victim to Mayumi's "special" chocolate. Afterwards, he gave a simple thanks before leaving the room.[2]
It can be said that the relationship between the two is one that is neither out of friendliness or hatred, but simply mutual respect.[9]
The Saegusa twins (Saegusa Kasumi & Saegusa Izumi)[]
Hattori is very afraid and cautious of them, which was shown when he was discussing with Azusa the next candidate to invite to the Student Council after Shippou's rejection. Just thinking about who the runner-up was in the entrance exams for First High made him look pale.[10] It is revealed in the conversation of the Saegusa sisters in Volume 11 (Visitor III), Chapter The Ojou-sama's Magnificent Day off, that the twins either scared or threatened him, personally or more probably by an intermediary, for trying to approach and court Mayumi.[11]
Kasumi has the same hostile attitude towards him that she bears towards Tatsuya.