Ishikawa Hachiemon is an anime exclusive character and one of the protagonists in Dr. Slump: Arale's Surprise.
Hachiemon is an older Asian man of average height and slender body. He has a large whitened mustache along with eyebrows of the same light. Hachiemon is bald and has distinct wrinkle marks around his cheeks, chin and temples. He dons a thick pair of rectangular glasses with a black frame.
Hachiemon is a wise, tactical, caring and easy-going individual. His once greedy side is revealed once he was exposed as the former World's Top Pirate. While he was more of a evil-doer with his stealthy scheming and pirating, Hachiemon became a more empathetic and loving person after he meets the Spring Spirits. He is confident in his skills as a pirate and go-getting in dire situations. Hachiemon can be occasionally grumpy and stern at times, but is generally calm and collected.
Arale, Gatchan, Akane, Taro, Peasuke, Obotchaman, King Nikochan and King Nikochan's servant meet Ishikawa Hachiemon when they travel to Wonder Island for a picnic. At first Hachiemon assumes the group are trying to hunt the Spring Spirits and attempts to chase them off the summit. After he realizes that they pose no threat to the spirits, he becomes friendly towards them. Arale and Gatchan discover the Fragment of the Sun and Hachiemon explains its importance to the Spring Spirits and their home.
Nashibaba arrives to the Island through his zeppelin, which is revealed to previously be owned by Hachiemon. Nashibaba taunts them, disclosing his past with Hachiemon as a disciple pirate. He proceeds to steal the Fragment of the Sun with his minions and retreats to the Secret Demon Realm.
Hachiemon pledges to retrieve the fragment from Nashibaba. The group doubt him and he reveals his secret past as the world's top pirate.
In a narrated flashback, Hachiemon is shown in his prime as a pirate who is wanted by the police. He ends up crash landing on an airplane atop Wonder Island's mountain summit. The man meets the Spring Spirits who happily keep him company with their carefree and playful nature. Hachiemon admired their purity and decided to reside in their home with a promise to protect them in return for their presence. He snagged the Fragment of the Sun to keep the mountain as warm as Spring year-round. He explains that humans have caused the weather to decline and the Spring Spirits die in the cold, so the fragment is a necessity.
Hachiemon reluctantly accepts Arale, Gatchan, Obotchaman and the Niko's request to accompany his quest. He plans to travel the world for three special treasures that will help him in following and traversing through the realm after Nashibaba. The three relics in question are The box that can lead to anywhere, The cloth that stretches at will and The Aladdin Lamp.
Akane, Peasuke and Taro stay back with the Spring Spirits as the group prepare to leave.
Hachiemon and company travel to China for the magic box, Paris for the magic cloth and a vault in an unnamed city for the lamp. They pirate the treasures from each area with relative ease and then enter the magic box to transport to the Secret Demon Realm.
Once everyone enters the realm through the box, they begin their journey towards Nashibaba's Base. King Nikochan and his servant separate from Hachiemon and crew. The top pirate assumes the aliens quit the rigorous quest and went home. Arale, Gatchan and Obotchaman adventure ahead with Hachiemon behind due to his older age. Though he is physically weaker than he once was, Hachiemon uses his wisdom and senses to safely travel. The three end up separating from Hachiemon due to their naivete but manage to meet back with him thanks to their abnormal abilities.
They find a room with an abundance of glass bottles and can't pass through due to the objects surrounding the passageway forward. Hachiemon warns them to be careful. Gatchan knocks down the bottles and triggers a trap. Nashibaba's underlings pop out of the bottles and attack them with their sharp bites. Since Arale and Obotchaman are robotic, the minions end up breaking their teeth against them and run away back inside the bottles pathetically.
The group continue and find Nashibaba's Base through a shortcut. Arale and Gatchan begin climbing and Hachiemon is suspicious. The stairway towards the base was in fact a trick by Nashibaba and part of the floating land of the realm begins to dissipate from existence. They evade the destruction thanks to Hachiemon making use of the magic cloth, which creates a lengthy pathway to travel up into Nashibaba's base.
Hachiemon and his crew raid the base and challenge Nashibaba who harbors many riches including the fragment of the sun. Hachiemon unsheathes a sword and Nashibaba aims a pistol, planning to dual. Arale, Obotchaman and Gatchan team-up with Hachiemon, causing Nashibaba to retreat after witnessing their power. Hachiemon stays back while the three pursue and overcome all of Nashibaba's tricks and obstacles.
They all meet up together and corner Nashibaba in his mech to take back the Fragment of the Sun. Nashibaba resists and takes cover for inevitable defeat by Arale and Obotchaman. Unfortunately the androids both die due to lack of Robovita-A and Gatchan is easily whacked away by Nashibaba's machine. Hachiemon begs him to stop beating the kids and Nashibaba delivers a finishing blow that sends their bodies away. Hachiemon and Gatchan are captured and nearly drown in a giant bottle contraption.
Arale and Obotchaman, revived with the help of the Nikos, break them free. They all confront Nashibaba again and he finally gives the fragment up.
Nashibaba uses a weather-altering device to create snow over Wonder Island in an attempt to kill the spring spirits. Hachiemon and the others try stopping it, but any interference caused the effect to grow stronger. Hachiemon decides they must retreat as Nashibaba triggers a self-destruction of his base and the demon realm itself. King Nikochan and his assistant lead the group to the zeppelin which they had previously stolen from Nashibaba from their absence. The group flees the destruction of the base, but the zeppelin gets engulfed in the destruction and are left to fend themselves.
Hachiemon pulls out the Aladdin Lamp and summons the Genie from within to help them escape. The genie ends up not knowing how to transport them back and disappears.
The portal to return back to their world emerges and everyone goes after it. After a few failing attempts to follow it due to the entrance's teleportation, Arale pulls out her trusty balloon. Hachiemon praises Arale for her great idea and she blows the balloon to a large size. Everyone grabs onto Arale as the balloon is quick enough to blow right into the portal back to their realm.
Hachiemon holds the Fragment of the Sun in his hat while they all safely return back to Wonder Island where their friends are waiting. They land down and the fragment is placed back where it belongs. The cold weather subsides and the stone brings back the spring weather for the weakened spirits.
Everyone reunites and the Spring Spirits play with them as gratitude for helping them. The group gives their farewells, flying away from the island in their plane.
Hachiemon is left in eternal peace with the Spring Spirits where he is never seen again.