- "Oh, I love you so much Su-darling! I wish I could mend our hands together so we'd never part!"
- —Setsuna Tachibana, in Pulling the Strings
Setsuna Tachibana is a major character in the series.
Sena's personality is pretty straightforward. For the most part she's just like any other girl, cute feminine, and friendly to those she considers her friend (those she doesn't find to be a threat). She can become rather violent and all around scary if she ever believes someone is trying to separate herself from Suigetsu, going as far as threatening to damage their personal belongings, hurting them, and ruining their lives. She's never had to get to that point, but she feels completely justified and would not hesitate to go through with it.
Sena's infatuation with Suigetsu stems from her desire to have someone she can really rely on. The two had lost someone dear to them and with that Sena found a deeply rooted connection something they would both suffer together. Since then, she had become rather possessive and it's grown into genuine affection and love for him. She doesn't always express herself the way she wants, and there are many times she wished she could love him like a normal girl would, but a deeply rooted fear of losing him completely keeps her from having a healthy relationship with him.
Because Sena enjoys cute things, she enjoys dressing up other girls and pretty boys. She likes to go shopping, and taking pictures and indulging in the charms of her friends. To those she decides to build a relationship with she treats them dearly and supports them in whatever makes them happy, but she will also work to motivate others and build up their confidence-something she doesn't realize she should be doing herself.