Reiha
The female protagonist, and one of the two playable characters. Reiha's father died 7 years before the game's main events.
- The Red Mage: Reiha can specialize in both offensive and support magic.
Aldo
The male protagonist, and one of the two playable characters. Aldo was accidentally summoned by Reiha seven years before the events of Twin Age.
- Clark Kenting: Though Reiha knows he's a Summon Beast, anyone outside of her inner circle pass him off as a human because the bandanna conceals the mark on his forehead.
- Disguised in Drag: In an attempt to infiltrate, he gets forced into a dress to conceal his identity. What dress he wears is dependent on the lead character, wearing a long purple dress if he's the lead, or a short blue one if Reiha is the lead.
- Heroes Prefer Swords: His starting weapon is a sword, and he has far more sword skills than axe or spear.
- Multi-Melee Master: With enough dedication, he can learn all the skills for each of his weapons. Doing so will give him access to Shine Viper.
Nessau
- Terrible Artist: Nessau is horrible at drawing others, but he thinks that his drawings are great.
Ayn
- The Medic: Ayn primarily specializes in healing magic.
Agneah
Ticah
- Support Party Member: All of Ticah's skills are based on healing or buffing her team members.
Phicra
Ghardib
Millisar
- Recurring Boss: Millisar's encountered and fought repeatedly throughout the game.
- Sixth Ranger: Towards the game's climax, Millisar ends up allying with the protagonists.
