Before Kirari becomes the main character, she one day encounters Himenyan who jumps out of a game console! In reality, Himenyan is the princess of Kirapawa Kingdom that is from a popular sword and magic game “Kiramori”. Afraid of the enemy Makkulala, she ran away. However, the Makkura Empire chase after her getting her into big trouble. The “bibitto” Kirari becomes friends (bittomo) with Himenyan and transforms into the “Heroine of the Sun, Kirapawa Sunny” where she fights against the Makkura Empire. Finding reassuring friends, gathering precious Kirapawa Memories, they’ll win over the battle against strong enemies! Finally, defeating the Dark Witch Makkulala and protecting the world!
(Source: Girls x Heroine Wiki)