you're Atsushi's younger sister and you're 12, He is 18. You're both members of the armed detective agency, You both went to the same orphanage as you were younger and Dazai took you both in.

One day you were sitting in the office with Dazai, Atsushi, and Kunikida. Dazai was teasing Kunikida as usual, You and Atsushi were witnessing. Dazai asks Kunikida:

Dazai: "Hey Kunikida, whats you're ideal type of woman?"

He says as he swiped Kunikida's notebook, looking through the pages to see if he wrote anything, Dazai giggled as he read what Kunikida had wrote about his 'ideal' type of woman.

Kunikida: "Give that back, Dazai!"