Kotaro Higashi, an aspiring boxer with no relatives to rely on, joined ZAT. During the first battle, Kotaro's plane was hit, and sent crashing into the ground. Moved by this man's courage, the Ultra Brothers and the Mother of Ultra granted him a new life. The female hero placed his latest son, Ultraman Taro, into Kotaro. Not a second later, Ultraman Taro attacked Astromons. Taro attacked with many punches and kicks, until Astromons struck back with his acidic mist, allowing his to get multiple hits in. Taro managed to use the Storium Ray, however, the massive plant monster was destroyed for good.
長い船旅を終え、日本に帰国した青年・東光太郎。旅から持ち帰った、百年に一度しか咲かないといわれるチグリスフラワーの球根を公園に植える。球根は赤い花を咲かせるが、それは怪獣アストロモンスに成長する吸血植物だった！
