Guide
How the kit works
Start with EX Special Attack: Cavity Alert (Special) when Yuzuha has enough Energy. It gives her 2 Sugar Points; a heavy hit applies Sweet Scare, and a hit also grants the squad Tanuki Wish and triggers a Quick Assist. Tanuki Wish lasts 40 seconds and gives the squad ATK and 15% DMG.
Switch to the teammate whose attribute you want to apply. When an active character first hits an enemy under Sweet Scare with an attack of their own attribute, Flavor Match changes Basic Attack: Sugarburst Sparkles and Basic Attack: Sugarburst Sparkles - Max to that attribute against that enemy. Reapplying Sweet Scare removes the existing match, so choose the next attacker again.
Sugarburst Sparkles strikes affected enemies every second. When another active character hits while Yuzuha has Sugar Points, Basic Attack: Hard Candy Shot can attack around the target. Its heavy hit consumes 1 point and triggers Sugarburst Sparkles - Max against enemies under Sweet Scare. Hard Candy Shot is an Aftershock and can trigger once every 8 seconds. The two Sparkles attacks build Anomaly, but their accumulated buildup does not contribute to the Anomaly DMG calculation.
Yuzuha starts with 3 Sugar Points and can hold up to 6. For more, parry with Basic Attack: Tanuki Cloak or Defensive Assist: Replenish Your Fun. After either parry, use Assist Follow-Up: Stuffed Hard Candy Shot at the right moment. Ultimate: Surrender or Suffer the Mischief also applies Sweet Scare on a heavy hit, gives 2 points and grants Energy to the other squad members.
Build and why
Use four pieces of Moonlight Lullaby and two of Phaethon's Melody. Moonlight Lullaby gives Energy Regen and, when Yuzuha uses an EX Special Attack or Ultimate, increases squad DMG by 18% for 25 seconds. Phaethon's Melody gives her 8% Anomaly Mastery, helping her reach her support threshold.
Astral Voice is another four-piece option: Yuzuha can trigger Quick Assists, which build its stacks and increase the DMG of the character entering through a Quick Assist. Swing Jazz is also worth considering for its squad DMG buff after a Chain Attack or Ultimate.
Choose Percent ATK on discs 4 and 5, and Anomaly Mastery on disc 6. Favor Percent ATK, then Anomaly Proficiency in substats. At 3,000 initial ATK, Yuzuha gives the full 1,200 ATK bonus from Tanuki Wish. With her Additional Ability active, 200 Anomaly Mastery gives its full buff.
Metanukimorphosis is the first weapon choice: its Physical EX Special Attack or Ultimate effect gives Anomaly Mastery, and its Aftershock effect gives the squad Anomaly Proficiency. Weeping Cradle is an alternative with off-field Energy Regen and a DMG increase against targets Yuzuha hits. Kaboom the Cannon gives the squad ATK when friendly attacks land.
Leveling priority
Follow the game's order: Core Passive: Whimsical Wonder first, then Basic Attack, Special Attack, Chain Attack, Assist and Dodge. The Core Passive contains Tanuki Wish; Basic Attack covers her off-field attacks, while Special Attack is part of her usual setup.
For maximum ascension, collect 800,000 Denny, 4 Basic Support Certification Seal, 32 Advanced Support Certification Seal and 30 Ruler Certification Seal.
To max all skills, you need 2,905,000 Denny, 25 Basic Physical Chip, 75 Advanced Physical Chip, 250 Specialized Physical Chip, 5 Hamster Cage Pass, 9 Sycophant's Refinement and 60 Higher Dimensional Data: Toxic Edge.
Mindscapes worth it
If you are comparing Mindscapes, I'd look at Full of Colorful Company first. Hitting with either EX Special Attack or Ultimate gives the squad 15% DMG and 15% Anomaly Buildup Rate for 40 seconds. It also shortens the cooldown of Basic Attack: Hard Candy Shot by 25%.
Put Down Roots is another upgrade to consider. It adds charge and extra shells to Assist Follow-Up: Stuffed Hard Candy Shot. A shell hit increases the squad's Disorder DMG Multiplier by 105% for 40 seconds, stacking up to three times.
Lucky Constitution is useful earlier: enemies under Sweet Scare lose 10% All-Attribute RES, and the Additional Ability's Anomaly DMG and Disorder DMG buff becomes 130% of its original value. Fairytale of the Haunted City and Dreams of a Fading Winter give skill levels rather than new team effects, so they are reasonable places to stop before if you do not want to go further.
Teams
Pair Yuzuha with an Anomaly character to activate her Additional Ability: The More the Merrier. A teammate from her faction also satisfies the condition. With it active, Anomaly Mastery above 100 increases Anomaly Buildup Rate and boosts Attribute Anomaly DMG and Disorder DMG, up to the limits reached at 200.
Miyabi is a Frost Anomaly option, while Alice is a Physical Anomaly character from Yuzuha's faction. Vivian is an Ether Anomaly option. For a third slot, Nangong Yu is an Ether Stun character; a Miyabi, Nangong Yu and Yuzuha team is worth trying. Let the character whose attribute you want hit after Sweet Scare is applied.
Common mistakes
Do not refresh Sweet Scare and then switch to the wrong attacker: the refresh removes the old Flavor Match. Check who hits first with their own attribute if you want a particular match.
Do not ignore Sugar Points. Basic Attack: Hard Candy Shot needs them, and its heavy hit spends one. Use an EX Special Attack or a successful parry to replenish the stock instead of staying on Yuzuha for long strings.
Do not chase Anomaly Mastery past 200 for a larger Additional Ability buff; its listed bonuses are already capped there. Likewise, Tanuki Wish's ATK bonus reaches its maximum at 3,000 initial ATK.