personality
Rantaro is a conserved, collected person, with an aura that can be mistaken for mysterious. He is described as one of the more ordinary students, with he himself stating that he can sometimes get a bit overwhelmed by the others' stranger personalities. Nevertheless, he is shown to have more patience than others. He also has a tendency to just laugh off some of the potentially hurtful things people may say.
Rantaro is usually seen smiling and describes himself as "not a suspicious guy,". He gives off a really calm and composed vibe, making him seem like a pretty reliable person. His speech is characterized by being very friendly and colloquial, too.
Despite his appearance and manner of speech, he has cold, excellent insight and is both determined and brave. He even has downright frightening expressions whenever he gets very serious. While the other students descend into confusion and chaos, he is capable of coldly interrogating them about their motives.
Rantaro also shows a deep understanding of the situation and often talks and acts like he knows something the others don't know, saying profound-sounding and enigmatic sentences, which often make him sound suspicious or even eerie.
People (especially girls) occasionally assume that Rantaro is a womanizer. He is aware that he looks like a "playboy," but he always insists he isn't that kind of person and doesn't have a girlfriend, stating that he's just a chill, friendly guy.
Rantaro dislikes it when people assume he is a womanizer or the kind of person to quickly hook up with someone based on his looks, possibly because his father might be one. He has had a few, but only because he felt genuine towards them.
The possibility of his sisters hating him and their safety in general appears to be his biggest concern, and even though he is seemingly a relaxed person, he is actually very stressed during the Killing Game, because he is very worried about his sisters and feels that he needs to get out fast in order to get back to them.
Rantaro tends to smile constantly even if he's actually feeling bad on the inside, which is supposedly a habit he developed due to having so many younger siblings to take care of. Very few times, when he gets a feeling that his sisters might accept him, he can have a real smile and laugh.
His biggest dream is to reunite his sisters and obtain their acceptance, and he is extremely dedicated to this dream, to the point that he once joked that he may have some sort of sister complex.