Hanta Sero/Relationships

Eijiro Kirishima
They are good friends with each other. Hanta and Eijiro were on the same team during the cavalry battle, along with Mina and Katsuki. Hanta and Eijiro work well together, as noted by how they cooperated in reeling in Katsuki during said cavalry battle.

Denki Kaminari
Denki and Hanta appear to be good friends, often hanging around and talking to each other, indicating a friendship. They share a very easygoing and social personality, tending to be among some of the louder and more extroverted boys of the class. They enjoy making jokes with each other, and appear to be very comfortable around one another.

Katsuki Bakugo
Hanta and Katsuki tend to be in close proximity due to their friendships with Eijiro. They were in the same team during the cavalry battle, where it was demonstrated that Hanta often gets exasperated with Katsuki's extreme competitiveness but is willing to cooperate with him regardless. Katsuki refers to him as "Tape Arms" or "Soy Sauce Face".

During the Joint Training Arc, they were paired on the same team and Hanta was inspired by Katsuki's declaration of leading them to a flawless victory. Hanta seems to have developed respect for Katsuki, as seen when he was grateful to Katsuki for saving their teammates when they were trapped.

Minoru Mineta
Hanta is often seen chastising Minoru for his perverse actions, though they get along as well.

They were paired up in their First Term Final Exam against Midnight and Hanta used his Tape to get Minoru away from Midnight's Quirk, leaving Hanta himself susceptible and thus incapacitated. However, due to Hanta's actions, Minoru was able to best Midnight and get him and Hanta through the exit.

Rikido Sato
Rikido and Hanta seem to be friends and to be good friends. They also seem to work very well as heroes and support their friends when needed. In fact, they carried an injured Thirteen and helped their classmates defeat Kurogiri during the U.S.J. Incident. They helped Ochaco Uraraka during the second part of the Provisional Hero License Exam using their Quirks to free civilians from debris. Most importantly, they had a key role in the fourth round of the Joint Training Battle, aiding their classmates with Rikido's power and Hanta's tape-support. They celebrated together when their team won.

During the events of the I-Island Incident, they were seen having dinner together and sharing a hotel room, implying they are friends.

Shoto Todoroki
Shoto and Hanta seem to be friends or at least good classmates. Hanta is seen cheering Shoto on when he was about to race Izuku and Katsuki in Season 3, Episode 1. In Chapter 218 of the manga, Hanta asks where Shoto is because he wants to borrow the next volume of a manga from him.