On August 25, the group held their first showcase in Tokyo Ariake Colliseum.[47] With an initial 10,000 fans invited, it was reported to be the most large-scale plan for a Korean artist debuting in Japan.[40] However, due to high number of expected attendees, the group's management announced that the showcase would take place three times in the same day rather than once to accommodate the estimated 20,000 fans.[48] The group sang 5 of their Korean tracks at each of the showcases, and the total number of attendees over all three shows were estimated to be at least 22,000.[49] At this showcase, the Genie Japanese music video was also revealed publicly for the first time, the teaser having been released a few days prior on August 20.[50]
Their Japanese debut single "Genie" debuted at the No.5 spot on the same day of its release on the Daily Oricon Charts and later rose to the No.2 position on the Daily Charts some time later, earning the group a No.4 position on the Oricon weekly ranking.[51][52][53] The group also hit the number No.1 spots on Japan iTunes' music video chart and both the Rekochoku daily video clip chart and incoming movie daily ranking chart a day later.[2] With pre-orders amounting to 80,000, the single sold an estimated 45,000 copies in the first week after release.[54][55] The single also placed high on Japan's Billboard chart, ranking No.4 on the comprehensive Hot 100 chart, No.5 on the Hot Single Sales Chart and No.1 on the Hot Top Airplay chart.