Since I don't know the specific 'quintuplets visual novel', I can't say for sure. But in a story about quintuplets, the quintuplets themselves would likely be the most interesting characters, each with their own distinct personalities.
The main characters are, of course, the quintuplets. They are five sisters, each with their own distinct personalities. There's Ichika, who is often seen as the more confident and outgoing one. Nino is known for her strong - willed nature. Miku is the shy and reserved sister. Yotsuba is the energetic and positive one. And Itsuki, who is often the more studious and responsible among them.
Well, of course, the quintuplets are the main characters. There's Ichika, Nino, Miku, Yotsuba, and Itsuki. Each of them has their own distinct personality. Ichika is the eldest and often takes on a leadership role among the sisters. Nino is the more assertive one, not afraid to speak her mind. Miku is the quiet and reserved type, often lost in her own thoughts. Yotsuba is the energetic and cheerful one, always bringing a positive vibe. And Itsuki is the studious and responsible sister.
The main characters are the quintuplets. But without having played it in detail, it's hard to say more about their individual personalities as presented in the visual novel specifically.
Yes, the Quintessential Quintuplets manga has come to an end. The final chapters tied up loose ends and gave closure to fans. It was a memorable journey throughout.