Despite his younger brother taking the ability to become Ultraman in stride, Katsumi is afraid of the power he’s obtained. Their younger sister, Asahi, whose catchphrase is “Happy♪”, uses her healing nature to help the two brothers, who have clashed over their views. Suddenly, a monster appears and Isami is unable to move when he’s pinned down.

凑兄弟深夜变身，研究奥特曼的性能。另外他们也产生了分歧，其中凑勇海认为他们变身奥特曼的秘密不能告诉任何人，而凑勇海认为自己是英雄，为什么不能告诉别人呢。弟弟因为不满哥哥而扬长而去，不过在他们妹妹的影响下两人联手和布莱克王战斗，刚开始还是被布莱克王压制，后来同心协力打败了布莱克王。

湊兄弟深夜變身，研究奧特曼的性能。另外他們也產生了分歧，其中湊勇海認為他們變身奧特曼的秘密不能告訴任何人，而湊勇海認為自己是英雄，為什麼不能告訴別人呢。弟弟因為不滿哥哥而揚長而去，不過在他們妹妹的影響下兩人聯手和布萊克王戰鬥，剛開始還是被布萊克王壓制，後來同心協力打敗了布萊克王。