Yuka's fondness in monsters started in her great-grandmother's hometown, , 18 years prior to the series. During her stay at her great-grandmother's home, after hearing the legend of Horoboros from her great-grandmother, she encountered the very monsters when she was lost in its territory at night. After STORAGE's disbandment, Yuka was relegated into a researcher in Monster Research Center until Juggler saved her from the GAFJ forces and rejoined STORAGE to rescue Yoko from Destrudos. When the monster was destroyed, Yoko and Kaburagi managed to catch Celebro for dissection.
