Stellactrum and Memory Sets: Love and Deepspace's Two Different "Constellation" Systems
Guides call it 星谱 (star chart) or "Constellation" — it's actually two unrelated systems wearing the same nickname.
When you see a guide mention a "Constellation" or 星谱 (star chart) system in Love and Deepspace, it's almost always talking about 星譜 — the six-color element (Emerald, Sapphire, Violet, Amber, Ruby, Pearl) stamped on every Memory's icon that decides its Ascension Crystal and gives a shield-break bonus when your team matches a battle's requirement. A completely separate feature often gets tangled into the same conversation: Memory Sets, the outfits your Battle Companions and Main Character unlock by ranking up paired Memories. This guide untangles both, plus the Myth Pair bonus that sits between them.
Neither the official English wiki nor the in-game menus use the word "Constellation" as a feature name. The nickname traces back to the Chinese term 星谱 (literally "star chart/spectrum"), which Chinese guide sites use to describe the 星譜 element system — six colors, matched to a card's element icon. English-language communities sometimes render that loosely as "Constellation." We treat 星譜 as the correct term throughout this guide, since that's what actually appears on the memory icon and the English wiki page.
Every Memory carries one of six Stellactrum types — Emerald, Sapphire, Violet, Amber, Ruby or Pearl — shown in the icon's upper-left corner, independent of whether the Memory sits in a Solar or Lunar slot. Some battles list a Stellactrum requirement (say, three Sapphire); fielding memories that meet or exceed it lets your team break two Wanderer shields per hit instead of one, a real combat advantage rather than a cosmetic label.
Every 10 levels, a Memory's cap needs raising with Ascension Crystals matching its own 星譜 color — Emerald Crystal for Emerald Memories, Sapphire Crystal for Sapphire Memories, and so on for Violet, Amber, Ruby and Pearl, each in N/R/SR tiers. This is exactly the material Bounty Hunt (the mode community guides nickname Zero-hour Pursuit / 零時追跡) farms: Pumpkin Magus pays Sapphire and Ruby Crystal, Lemonette pays Emerald and Amber, Snoozer pays Violet and Pearl. Figure out which color is bottlenecking your build, then farm the matching bounty.
A Battle Companion (Zayne: Foreseer, Rafayel: Abysswalker, and so on) is unlocked the moment you pull a copy of either Memory in its required pair. Ranking that Companion's memories up to R1 — meaning you've collected enough duplicates or shards — unlocks its Regular Color outfit Set, worn during that Companion's related Myth story. Reaching R2 unlocks a Special Color alternate Set.
As of this writing, item data shows dozens of these Battle Companion Sets already live across the five Love Interests — the newer Caleb and Sylus currently have fewer Sets than the original three, a gap that should close as their rosters catch up. The Main Character has a parallel, separate line of "My Outfits" Sets tied to the same Myths.
Some Solar Memories are pre-linked as a Myth Pair — the same paired memories that unlock a Companion and its Myth story. Fielding both in battle triggers a Memory Pair bonus, and ranking both up further scales it through Duo Rank 1, 2 and 3, covering effects like team DMG, Ardent Oath charge and damage reduction. The bonus grows with each Duo Rank and scales higher for 5-star pairs than 4-star pairs, with additional pair-specific effects layered on top — but the exact percentage at each rank isn't reliably cross-checked yet, so check the in-game Duo Rank panel for the current value rather than treating any number here as fixed.
Don't chase outfit Sets or Duo Rank bonuses before your core Memories can actually survive a fight. The order that pays off fastest: level and Ascend your main Memories first (farming the matching Bounty Hunt crystals as you go), then match battle Stellactrum requirements for the shield-break advantage, and only then start collecting duplicates toward R1/R2 for the outfit Sets and Duo Rank bonuses — those are the payoff for investment you'd be making anyway, not a separate grind to prioritize early.