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JAPANESE ORIGINAL / Japanese GB releases: Ruka / Iru

DQM2 GB | Progressing through the Desert World and where to use Yobimizu

Preparations after Slash joins, reporting the water shortage, the dungeon, and the Phantom Lake: follow the GB versions' shared events in order.

Content checked: 2026-10-14 / Source materials checked: 2026-10-13

Japanese Game Boy versions of DQM2: Maruta's Mysterious Key — Ruka's Departure / Iru's Adventure / Not independently tested on original hardware or an emulator. This explanation cross-references official game information and publicly available guides.

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About this page

Versions covered: Japanese GB releases Ruka's Departure and Iru's Adventure. This guide covers shared Desert World events. To avoid version differences in monster appearances and stats, it does not prescribe specific companions or required levels.

If you cannot progress in the Desert World, check whether you have reported to the king and received Yobimizu in the dungeon before continuing to train. Conversation order and where you use items are the keys to progression in this world.

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1. Prepare healing supplies and monster recruitment in Maruta

Once Slash the slime joins you, speak to both parents before leaving. Your mother gives you medicinal herbs, and your father gives you smoked meat. Then use the Oasis Key at the door deep inside the well to travel to the Desert World.

Recruit more companions in the desert and assemble a party of three monsters before starting the circus event in Assia. If you reach town with only Slash, recruit monsters nearby before returning.

You do not need to spend ages searching for breeding material at this stage. Breeding in the GB versions becomes available after clearing the Water World.

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2. Report the water shortage in Assia

After hearing what people in Kalkara have to say, head to Assia and speak to the circus leader outside the inn to enter the castle. After the performance, hear the king's request, ask the woman near the town well about the water shortage, and report back to the king.

When the king heads for Kalkara, follow him. Enter the underground waterway from Kalkara's floodgate and defeat Bibaan at the far end to advance the water shortage investigation.

If progress stalls, check that you did more than speak to the woman at the well. Reporting to the king is part of the same sequence. Check HP and healing items before entering the waterway, too.

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3. When the treasure is stolen, head to the dungeon

After the Bibaan battle, return to Assia Castle and speak to the king. Once you learn that the treasure has been stolen, give food to the prisoner in the castle dungeon to receive Yobimizu. Accepted food includes monster feed and smoked meat.

If you used up your meat while recruiting, obtain food before returning. Walking around the lake without Yobimizu will not let you reach the place you need.

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4. Use it in front of the puddle at the Phantom Lake

At the Phantom Lake, use Yobimizu as an item in front of the puddle left after the lake disappears. Simply obtaining it does not complete the event, so check where to use it as well.

Once you can enter the lake, head to the thieves' hideout and advance the event by completing the battle with the cursed lamp. The Desert World segment ends after you obtain the Uminari no Kane bell and return to Maruta.

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Checks to make when you are stuck

  • Cannot enter the castle: check your party and speak to the circus leader outside the inn
  • Floodgate event will not advance: report the well woman's account to the king
  • Cannot enter the Phantom Lake: obtain Yobimizu in the dungeon and use it in front of the puddle
  • Want to breed monsters in the desert: continue with your current companions and work toward clearing the Water World first

This article does not use boss HP as a target to aim for. Prioritize healing and prepare your party before each battle.

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