Arin is bouncy- in more ways than one- and very easy to approach for a kidnapping so long as she doesn't sense any danger from it, so it's best to treat the captivity as a game. Even though she's a top student, she's very naive so it's easy to trick her and keep her tied up just as long as she's unable to use any magic, so gag her quickly. Utilize ties that emphasize her chest and gags that emphasize her hair but don't cover a lot of face as she is very prone to blushing. Don't utilize poses or actions that risk her modesty, otherwise she will surprise one with her strength. So long as she can enjoy herself, she usually won't complain.