IRIA is the story of a young woman -- calm, competent, and beautiful -- who idolized her brother Gren, a bounty hunter. Underage and a restless apprentice, she could not take on any mission unless supervised by a licensed hunter. She would accompany her brother on all his missions, learning all he had to teach, much to the amusement of Bob (their go-between) and the irritation of Fujikuro (a hot-headed, money-crazy, reckless occasional-partner with a long ratty mustache). All of that changed when Bob brought news of a great job, one involving freeing hostages on a spaceship taken over by terrorists and returning the cargo to their home planet, Myce. As usual, Fujikuro was left out, but this time it saved his life. The terrorists turned out to be the "cargo," an unkillable, unstoppable, and undeniably ugly alien being called Zeiram.

Episodes 1, 2, and 3 tell of how Bob was mortally injured by Zeiram and how Gren stayed behind on the spaceship and apparently died when it self-destructed. Iria escaped in a little shuttle and was blown onto the planet Tau Wa Dchan, where she met up with a brash young thief, Kei, who stole her shuttle, her food, the necklace that Gren had given her, and her hair beads -- in that order. She also had an encounter with Zeiram but managed to teleport him out of the planet. Returning to Myce, she found her house ransacked, all records of the mission erased, all the people from the space station listed dead, and the planet's soldiers out to kill her. Helped by Fujikuro and a mysterious voice that sounded strangely familiar, Iria evaded the soldiers and sought out the man responsible for letting Zeiram loose -- Putobaya. There she found that the voice she had been hearing was Bob -- his being trapped in a computer as an experiment that Putobaya had sanctioned.

Tonight's episode, 4, takes place on Iria's birthday. Finally old enough to be eligible for full bounty hunter status, she fights against a simulated Zeiram to get her license -- no problem at all after having fought the real thing. In the meantime, her short thieving admirer, Kei, is in big trouble on his own world. The government has decided to clean up the garbage on that tropical tourist planet. The streets are total chaos, where open war is taking place, so Kei has a brilliant idea: he would go search for the lovely lady who kicked butt so well. Making up a story of far-off relatives, Kei drags his friend Komimasa along as he sneaks onto a spaceship headed for Myce. But the ship they choose has one more passenger of literally earth-shattering importance.......... Dr. Toka, the only scientist with any information on the deadly alien organism called Zeiram.........