Yesterday Calls

Max-level stats (Lv60)

Base ATK (Lv.60)

713

CRIT Rate (Lv.60)

24%

Rank

S

W-Engine effect

Rank SStun

24/7

While off-field, the equipper's Energy Regen increases by 1.5/s. When the equipper deals Physical DMG with an EX Special Attack, the Daze dealt by the equipper's attacks increases by 9% for 10s, stacking up to 3 times. At 3 stacks, all squad members gain 30% additional CRIT DMG for 40s. Repeated triggers reset the duration. Only one instance of this CRIT DMG boost effect can exist in the same squad. *Stats shown are at Base level.

Overclock Table (★1 → ★5)

Official values straight from the publisher — every duplicate copy Overclocks the passive by one star, capped at ★5.

Upgrade	★☆☆☆☆	★★☆☆☆	★★★☆☆	★★★★☆	★★★★★
Equipper's Energy Regen increases	1.5/s	1.7/s	1.9/s	2.1/s	2.3/s
Equipper's Daze increases	9%	10.3%	11.7%	13%	14.5%
Squad CRIT DMG increases	30%	34.5%	39%	43.5%	48%

Materials & Stats per Breakthrough Milestone (0 → 60)

The full ATK/sub-stat curve across all 7 milestones plus the materials each one costs, read straight from official data.

Lv.	Before	After	Material
Lv.0	Base ATK: - CRIT Rate: -	Base ATK: 48 CRIT Rate: 9.6%
Lv.10	Base ATK: 123 CRIT Rate: 9.6%	Base ATK: 166 CRIT Rate: 12.5%	Denny ×12,000 Stun Component ×4
Lv.20	Base ATK: 241 CRIT Rate: 12.5%	Base ATK: 284 CRIT Rate: 14.4%	Denny ×28,000 Reinforced Stun Component ×12
Lv.30	Base ATK: 359 CRIT Rate: 15.4%	Base ATK: 402 CRIT Rate: 18.2%	Denny ×60,000 Reinforced Stun Component ×20
Lv.40	Base ATK: 477 CRIT Rate: 18.2%	Base ATK: 520 CRIT Rate: 21.1%	Denny ×100,000 Specialized Stun Component ×10
Lv.50	Base ATK: 595 CRIT Rate: 21.1%	Base ATK: 638 CRIT Rate: 24%	Denny ×200,000 Specialized Stun Component ×20
Lv.60	Base ATK: - CRIT Rate: -	Base ATK: 713 CRIT Rate: 24%

Total materials for the full 0→60 climb

Denny ×400,000 Stun Component ×4 Reinforced Stun Component ×32 Specialized Stun Component ×30

Where To Farm

Combat Simulation — each Enemy Card costs 20 Battery, up to 5 cards per run (100 Battery for a full run).

Signature Holder

Yesterday Calls's exclusive signal W-Engine — equip it on the matching Agent to unlock the signature outfit.

Dialyn

Best Agents for this W-Engine

Recommended for

S

Dialyn S+

How to Get This W-Engine

Pull it from Signal Search using Master Tapes / Encrypted Master Tapes (bought with Polychrome) — S-rank W-Engines get their own banner, usually alongside the matching character's banner.

Trade for it at the Gadget Shop's Box Galaxy section (Sixth Street): costs W-Engine Components + W-Engine Chips + Denny; Chips come from disassembling spare W-Engines.

A handful of A/B-rank W-Engines unlock through Proxy Primer trials or as story/event rewards instead of the gacha — not every W-Engine is pullable.

Compare with Same-Specialty Picks

Other Stun-specialty W-Engines, sorted by rank — solid stand-ins while you don't have the signature.

W-Engines	Rank	Base ATK (Lv.60)
Yesterday Calls	S	713
Chief Sidekick	S	713
Neon Fantasies	S	713
Roaring Fur-nace	S	713
Spectral Gaze	S	713
Ice-Jade Teapot	S	713
Blazing Laurel	S	713

Official Artwork / Lore

Riiiing, riiing — every missed call from the Hollows will be answered by Krampus' top-tier customer service! That playful line hardly captures the weight of old obsessions, grudges, and regrets carried through those calls. But in truth, it's the most earnest vow of one prepared to bear that burden. "Everyone else enters the Hollow armed to the teeth. Why am I the one carrying a bunch of phones?" —Dialyn, venting to her boss about her assigned gear.

Alternatives of the same specialty

Stun specialty — decent picks while you don't have this one

Chief Sidekick

Neon Fantasies

Roaring Fur-nace

Spectral Gaze

Ice-Jade Teapot

How to read this W-Engine page

Every W-Engine has 5 Refinement ranks (R1→R5): refinement ONLY strengthens the passive effect — the numbers in the table above run from left (R1, unrefined) to right (R5, max refinement via 4 duplicates or Overclock materials); Base ATK and the Advanced Stat (CRIT Rate/CRIT DMG/ATK%/PEN Ratio/Anomaly Proficiency...) do NOT change with refinement, only with the engine's level. "Best Agents for this W-Engine" prioritizes agents whose real build actually recommends this engine; if that data isn't available yet, the page falls back to agents sharing the same specialty as a rough guide. "Alternatives of the same specialty" lists other W-Engines with the same role — useful when you don't own the engine shown on this page.

FAQ

What is Yesterday Calls in Zenless Zone Zero?

Yesterday Calls is a rank S W-Engine built for the Stun specialty in Zenless Zone Zero — equip it on an Agent of the matching specialty to unlock the full passive effect; see the base stats and the full R1→R5 Refinement table in the sections above.

Which Agents should use Yesterday Calls?

Yesterday Calls fits Stun specialty Agents best, with 1 recommended characters including Dialyn — see the full list with portraits in the "Best Agents for this W-Engine" section above.

How much Denny and material does it take to upgrade Yesterday Calls, and where do I farm it?

Leveling Yesterday Calls through every milestone takes roughly 4 W-Engine components and Denny ×400,000, Stun Component ×4, Reinforced Stun Component ×32 Denny combined — the components drop from Combat Simulation; see the exact breakdown per milestone and the Battery cost in the "How Much You Need" and "Where to Farm" sections above.

Is Overclocking Yesterday Calls worth it?

Overclocking only strengthens Yesterday Calls's passive effect from ★1 up to ★5 (5 copies) — it never changes Base ATK or the sub-stat, so getting the base copy matters far more; treat extra copies as a bonus.

Where do I get Yesterday Calls?

Mostly through Signal Search gacha (Polychrome); a few A/B-rank W-Engines are tradeable at the Gadget Shop's Box Galaxy or come from story/event rewards — see the "How to Get" section above for details.