You'll need to have completed
first before you can take on these series of sidequests.
Once Koichi returns to The Outpost with you, he'll be to the right of Esther. He'll have a series of six quests to help him open a museum on The Outpost. These quests can either be really fast, or take quite a while, depending on both the RNG of the planets you've already found beforehand, and if you've been scanning every new object you've come across in the game. As with a Pixel Printer, almost everything you've scanned in the game can be created using Pixels, including all the quest items needed for his six quests. I'll be including the wiki links for all the items, so you can see what they look like.
The first item he wants you to find is a Grand Avian Sarcophagus, most likely to be found in Avian Tombs, and somewhat likely to be found in Avian Native Villages. Both this dungeon and village are more likely to be found on Jungle planets.
https://starbounder.org/Grand_Avian_SarcophagusThe second item is a Big Ape Bust, now this one was a giant pain, and was literally the only object I had a hard time finding. Every other object he needs for his quests, I had already found or scanned before I returned to The Outpost with him. But this one took me quite a long time to find. It's found in Apex City Apartments, more likely to appear on Tundra planets. But it needs to be a very specific version of these Apex City Apartments, I want to say I found 15+ before I finally found a planet that had a Big Ape Bust. It was such a pain, I'm going to write down the coordinates for the planet I found mine on. As far as I can tell, coordinates are essential a seed, like in Minecraft worlds. So you should be able to enter my coordinates on your galaxy map, and it will create the same planet in your game. -115706399 in the top line, and 558351290 in the bottom. So hopefully that will help for others who couldn't easily find this dumb Bust.
https://starbounder.org/Big_Ape_BustThird item is a Floran Statue. Found in Floran Hunting Grounds, and Floran Hut Villages. Both are more likely to appear on Forest planets.
https://starbounder.org/Floran_StatueFourth item is an Armed Display Armour. This is only found in Glitch Castles, which are more likely be appear on Volcanic planets.
https://starbounder.org/Armed_Display_ArmourThe fifth is an Old Television. It can be found in quite a few places. Human Campsites, Swamps, and others of what the game called microdungeons. I personally found a ton in Swamps. The Campsites don't have a planet they are more likely to appear on, and Swamps are found on Forest and Jungle Planets.
https://starbounder.org/Old_TelevisionThe sixth and last item he wants for his museum is a Traditional Gong. Found in Hylotl Underwater Ruins and Hylotl Ruined Castles. The Underwater ruins are only found on Ocean planets, while the Hylotl Ruined Castles are dungeons that can appear on all planet types that allow dungeons. I would say Ocean planets would probably be your best bet for this item.
https://starbounder.org/Traditional_GongOnce you hand them all over to Koichi, you'll unlock this achievement, plus you can actually visit this small completed museum using the teleporter at the 2 Stop Teleshop in The Outpost.