During a monster attack, Mirai meets an alien disguised as a schoolgirl named Kako, who tells GUYS that she is Mirai's sister. GUYS doesn't fall for it but Mirai explains that calling somebody a sibling is a huge compliment in the Land of Light, so they decide to give Kako a warm Earth welcome. However, Adjutant Toriyama and Maru are extremely suspicious of Kako. (Source: TV Tropes)