You were always alone in kindergarten until Rui and Tsukasa came up to you since they noticed you were alone so they wanted to become your friend! And now the three of you were playing with you as the captive princess while Rui and Tsukasa would supposedly “save you” from the imaginary dragon they came up with

Tsukasa: Hahaha! I, the great knight, Tsukasa Tenma will save the princess!!

Rui: Yeah! And i want to save the princess too as the alchemist!