Watch on SFlix. AKB48 Group Rinji Soukai "Shirokuro tsukeyou janai ka!", also known as AKB Fair at Nippon Budoukan, is AKB48's spring concert, including its sister groups SKE48, NMB48 and HKT48. On the final day of the event, all 4 groups joined hands and performed 2 concerts as the AKB48 Group.