OP-16 The Hour of the Decisive Battle: Set Guide (Boxes, Cards and Chases)

One story arc defined One Piece more than any other, and the card game keeps coming back to it: the Summit War. OP-16 The Hour of the Decisive Battle — also distributed in parts of Europe as The Time of Battle — brings the game back to Marineford and Impel Down, with a cast that smells of legend and one of the year's most sought-after chase lineups. In this guide: what the set contains, the six Leaders, the cards everyone hunts, the English vs Japanese box comparison and the criteria to buy well.

Key Takeaways

1. Marineford, Act Two

The card game had already touched the Summit War with OP-02, back when the game was taking its first steps. OP-16 returns to it grown up: Impel Down and Marineford live again with today's production level — brand-new illustrations, mature parallel treatments and a cast crossing Ace, Yamato, Koby, Ivankov, Inazuma and the Navy's great names. It's the year's "emotional" set: the manga's most beloved arc, revisited when the game finally has the means to do it justice.

The release followed the now-usual double track: Japan in late May 2026, English in June. In Europe the set circulates under two names — The Hour of the Decisive Battle and The Time of Battle depending on distribution — but the content is the same: if you're hunting the set, hunt them both.

2. The Six Leaders

OP-16 brings six Leaders to the table: Monkey D. Luffy (blue/green), Portgas D. Ace (red), Buggy (blue), Sengoku (purple), Yamato (black) and Marshall D. Teach (black/yellow). It's a roster built on Marineford's protagonists — with Ace naturally at center stage, including the Leader alt-art version that ranks among the set's most hunted cards.

For players, Sengoku and Yamato brought fresh archetypes to the meta; for collectors, the Ace/Teach pair moves the market. The two worlds, as always in this game, talk to each other: a Leader strong in the meta supports demand for its rare versions.

3. The Chases: The Admirals in Manga Treatment

The set's cover story, for the market, is the manga rares of the three Admirals: Sakazuki, Kuzan and Borsalino in the "comic" treatment reproducing the manga panel. It's the first time the Navy trio receives the game's most prized treatment together, and Japanese marketplace quotes placed them among the year's most sought-after cards from day one.

Behind them: the Treasure Rare dedicated to the Impel Down prisoners — one of the set's most original cards — the Secret Rares, the Specials and heavyweight alt-arts like Edward Newgate. As always, condition and centering make the price: on cards of this tier, the gap between a raw copy and a certified high grade is substantial — the criteria are in our graded One Piece cards guide.

Did You Know?

OP-16 is the game's second set dedicated to the Summit War after OP-02 — but it's the first to give all three Admirals the manga rare treatment in the same set. A trio that made the fortune of those who opened the first Japanese cases.

4. English or Japanese Box?

It's the question we get most often, and on OP-16 it counts double because the Japanese set arrived weeks earlier. In short: the Japanese box generally costs less for the same content, releases earlier and has historically consistent print quality; the English box is more liquid on the Western market, more immediate for European tournaments and more recognizable at resale.

Singles' values follow population and demand logics we analyzed in the One Piece English vs Japanese guide: the practical rule is choosing the language based on your goal — opening, collecting or investing — not out of habit.

5. Buying OP-16 Today: Boxes, Cases and Singles

A few months after release, OP-16 is in the most interesting phase for methodical buyers: day-one hype has passed, the set is still in circulation and the chases have found their price. The three roads: the sealed box (ENG or JAP) for the opening experience, the case for those thinking like sealed investors, and singles for those going straight for the cards their collection is missing.

In our OP-16 collection you'll find all three: boxes and cases in both languages from the One Piece booster box section, plus singles verified card by card. And for three-figure chases and up, the usual rule applies: real photos, verifiable seller and — whenever possible — a certified slab.

6. OP-16 as a Collection Piece

No promises — collecting is not a guaranteed investment — but OP-16 shares three traits with historically strong sets: a central story arc in the One Piece canon, cross-appeal chases that speak to Navy collectors and Ace fans alike, and a print window that sooner or later closes. When a set stops being reprinted, demand shifts entirely onto circulating copies: it's the dynamic we've seen on the game's historic sets.

Build a position with criteria: well-kept sealed, singles in excellent condition — and for top pieces, certification. PSA, BGS and GRAAD submissions run directly through our grading service managed from Italy, with real-time quotes.

7. Where It Sits: From OP-15 to OP-18

OP-16 arrives after OP-15 Adventure on God's Island and before OP-17 The World's Strongest Warriors, the set that closed summer 2026. On the horizon there's already OP-18 The Dominance of God, expected in November. To place every set in the game's complete line — from Romance Dawn to today — there's our map of all One Piece sets, and to start from the basics, the complete One Piece Card Game guide.

In a set's life cycle, the moment it "exits" the novelty stage is often when it enters its true collecting phase: OP-16 is entering it now.

Conclusion

OP-16 The Hour of the Decisive Battle is the card game's return to One Piece's narrative heart: six Leaders, the Admirals in manga treatment, a memorable Treasure Rare and an ENG/JAP double track that rewards those who choose with criteria. Whether you want to open, complete or invest, you now have the full picture.

At GS Gameon we follow every One Piece set from day one: boxes and cases in both languages, verified singles, graded cards and honest advice on what's truly worth it. OP-16 is waiting in our collection — and if you've already found your chase, you know where to certify it.

Note: dates, contents and quotes cited reflect information available at publication and may change. Card values depend on condition, demand and the market; past performance does not guarantee future results.