Most Popular Online Casinos in June

EnergyCasino

Enjoy 30 Free Spins plus a ¥50,000 Welcome Package

Sign-up Bonus:

30

Free Spins

No deposit required

Significant terms: 18+. 30 Free spins (Spins value: $0.10) on Book of Dead™ slot machine available once, to new customers who register at EnergyCasino using the promotional link. Maximum winnings $100. Spins expire after 7 days. · Terms & Conditions apply  ·  Play responsibly

EnergyCasino

Enjoy 30 Free Spins plus a ¥50,000 Welcome Package

  • 30 Free Spins · No deposit required
  • No-deposit Bonus exclusive to new players from Japan
  • 100% bonus up to ¥25,000 with your first deposit (New customers)
  • EnergyCasino offers exclusive bonuses for CasinoBonusCenter visitors
  • Bonus available on your second purchase
  • Japanese players are accepted
  • Play instantly in your browser – No installation required
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at EnergyCasino
  • Over $11,440,114 in Jackpots by Games Global
  • Tested and certified by Casino Bonus Center · Rating: 4.4/5
  • Popularity: This offer has been claimed by 213 visitors so far this month.
  • 65 Game Providers: Pragmatic Play, NetEnt, NetGaming, Evoplay, Play n GO, Big Time Gaming, Merkur Gaming, NolimitCity, BF Games, Bally Wulff, Just for the Win, Iron Dog Studio, and others.

KikoBet

Unlock a €500 Welcome Package – Your Gateway to Premier Casino and Sports Betting Thrills!

Welcome offer:

100% Bonus up to

€200

Bonus on first deposit

Terms & Conditions apply ·  Play responsibly

KikoBet

Unlock a €500 Welcome Package – Your Gateway to Premier Casino and Sports Betting Thrills!

  • 100% bonus up to €200 with your first deposit (New customers)
  • KikoBet offers exclusive bonuses for CasinoBonusCenter visitors
  • Bonus available on your second and third deposit
  • Japanese players are accepted
  • Accepts Bitcoin and other cryptocurrencies
  • Play instantly in your browser – No installation required
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at KikoBet
  • Online sports betting
  • Tested and certified by Casino Bonus Center · Rating: 4.1/5
  • Popularity: This offer has been claimed by 113 visitors so far this month.
  • 26 Game Providers: Pragmatic Play, Spribe, Vibra Gaming, Salsa Technology, Evolution Gaming, iSoftBet, Yggdrasil Gaming, Casino Technology, Playtech, Gamzix, Play n GO, Foxium, and others.

ReloadBet

Online sports and casino betting · $300 welcome bonus!

Welcome offer:

100% Bonus up to

$300

Bonus on first deposit

Terms & Conditions apply ·  Play responsibly

ReloadBet

Online sports and casino betting · $300 welcome bonus!

  • 100% bonus up to $300 with your first deposit (New customers)
  • ReloadBet offers exclusive bonuses for CasinoBonusCenter visitors
  • Japanese players are accepted
  • Accepts Bitcoin and other cryptocurrencies
  • Play instantly in your browser – No installation required
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at ReloadBet
  • Online sports betting
  • Over $11,440,114 in Jackpots by Games Global
  • Tested and certified by Casino Bonus Center · Rating: 3.9/5
  • Popularity: This offer has been claimed by 99 visitors so far this month.
  • 32 Game Providers: Play n GO, 3 Oaks Gaming, iSoftBet, Salsa Technology, Yggdrasil Gaming, Evolution Gaming, Red Tiger, Spribe, BRAGG, Blueprint Gaming, Playtech, Vibra Gaming, and others.

SlottoJAM

$500 welcome reward, weekly tournaments and VIP Club

Welcome offer:

100% Bonus up to

$200

Bonus on first deposit

Terms & Conditions apply ·  Play responsibly

SlottoJAM

$500 welcome reward, weekly tournaments and VIP Club

  • 100% bonus up to $200 with your first deposit (New customers)
  • Bonus available on your second purchase
  • Japanese players are accepted
  • Accepts Bitcoin and other cryptocurrencies
  • Play instantly in your browser – No installation required
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at SlottoJAM
  • Online sports betting
  • Over $11,440,114 in Jackpots by Games Global
  • Tested and certified by Casino Bonus Center · Rating: 3.5/5
  • Popularity: This offer has been claimed by 92 visitors so far this month.
  • 103 Game Providers: Hacksaw Gaming, Synot Games, Buck Stakes, Salsa Technology, Just for the Win, Indigo Magic, Reevo, Amatic, Endorphina, Neko Games, Hammertime Games, Vibra Gaming, and others.

GambleZen Casino

Discover Nature’s Hidden Treasures with €3,625 in Your Backpack

Welcome offer:

200% Bonus up to

€500

+ 100 Free Spins

Bonus on first deposit

Terms & Conditions apply ·  Play responsibly

GambleZen Casino

Discover Nature’s Hidden Treasures with €3,625 in Your Backpack

  • 200% bonus up to €500 + 100 Free Spins with your first deposit (New customers)
  • GambleZen Casino offers exclusive bonuses for CasinoBonusCenter visitors
  • Bonus available on your second and third deposit
  • Japanese players are accepted
  • Accepts Bitcoin and other cryptocurrencies
  • Play instantly in your browser – No installation required
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at GambleZen Casino
  • Tested and certified by Casino Bonus Center · Rating: 4.2/5
  • Popularity: This offer has been claimed by 84 visitors so far this month.
  • 86 Game Providers: Platin Gaming, Ezugi, Onlyplay, OctoPlay, Fugaso, Pragmatic Play, LiveGames, XProGaming, KA Gaming, Evolution Gaming, Betsolutions, Playtech, and others.

Grande Vegas

Get 50 free spins and a welcome package of $300!

Sign-up Bonus:

50

Free Spins

No deposit required

Terms & Conditions apply ·  Play responsibly

Explore bonuses at Grande Vegas

Grande Vegas

Get 50 free spins and a welcome package of $300!

  • 50 Free Spins · No deposit required
  • Bonus Code: 50FREESPINS
  • 150% bonus up to $300 with your first deposit (New customers)
  • Bonus Code: WELCOME
  • Bonus available on your second purchase
  • Japanese players are accepted
  • Accepts Bitcoin and other cryptocurrencies
  • Play instantly in your browser – No installation required · Optional game downloads available
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at Grande Vegas
  • Tested and certified by Casino Bonus Center · Rating: 3.2/5
  • Popularity: This offer has been claimed by 73 visitors so far this month.
  • Game Providers: SpinLogic and Visionary iGaming

Slotastic

Enjoy 50 Free Spins—No Deposit Required—Plus a 250% Bonus and 50 Extra Spins!

Sign-up Bonus:

50

Free Spins

No deposit required

Terms & Conditions apply ·  Play responsibly

Explore bonuses at Slotastic

Slotastic

Enjoy 50 Free Spins—No Deposit Required—Plus a 250% Bonus and 50 Extra Spins!

  • 50 Free Spins · No deposit required
  • Bonus Code: ENJOY50
  • 250% bonus up to $250 + 50 Free Spins with your first deposit (New customers)
  • Bonus Code: MATCHTASTIC
  • Slotastic offers exclusive bonuses for CasinoBonusCenter visitors
  • Bonus available on your second and third deposit
  • Japanese players are accepted
  • Accepts Bitcoin and other cryptocurrencies
  • Play instantly in your browser – No installation required
  • Mobile-friendly games · Enjoy playing on smartphones and tablets
  • Live Casino · Play against real croupiers at Slotastic
  • Tested and certified by Casino Bonus Center · Rating: 3.4/5
  • Popularity: This offer has been claimed by 67 visitors so far this month.
  • Game Providers: SpinLogic and Visionary iGaming

Top 10 Online Casino Bonuses in Japan (June 2025)

Expert-Rated Real Money Casinos with Top Bonuses

Looking for the best online casinos in Japan? Our expert team has tested and reviewed hundreds of real money gambling sites to bring you the top 10 choices for June 2025. bitStarz, Zodiac Casino, and SnatchCasino lead our rankings, standing out for their extensive selection of high-paying slots, immersive live dealer tables, exclusive bonuses, and lightning-fast payouts.

Browse our expert-ranked list below and claim your exclusive welcome bonuses today!

Online Casinos JapanWelcome Bonus

Claim up to ¥50,000 in Bonuses

Bonus of 100% up to ¥10,000 + 180 Free Spins

80チャンスは億万長者になるために!

80 Free Spins

Casino Fun, Beach Vibes, Gangster Style

Bonus of 225% up to $1,000 + 100 Free Spins

Daily slots tournaments

Bonus of 100% up to $400

$900 Welcome bonus + 110 extra spins!

Bonus of 100% up to $300 + 100 Free Spins

Get a free spin on the wish wheel!

Bonus of 100% up to $1,000

Sportsbook, casino, live casino

Bonus of 100% up to $100 + 50 Free Spins

The best games, all in a safe place

Bonus of 100% up to $200 + 200 Free Spins

ジャックポットが当たる150回のチャンスをゲット

150 Free Spins

30 free spins plus ¥50,000!

Bonus of 100% up to ¥25,000

* Terms & Conditions Apply ·  Play responsibly

With nearly two decades of experience in the industry, CasinoBonusCenter.com has been analyzing and comparing online casinos since 2006. Our dedicated team of professionals has handpicked the most trusted casinos for Japanese players to ensure you get the biggest sign-up bonuses, top-tier games, and the most rewarding loyalty programs.