Most Popular Online Casinos in August

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)
  • Bonus available on your second and third deposit
  • KikoBet 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 KikoBet
  • Online sports betting
  • Available in multiple languages, including English
  • Tested and certified by Casino Bonus Center · Rating: 4.1/5
  • Popularity: This offer has been claimed by 199 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.

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 Gates of EnergyCasino 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
  • Exclusive No-Deposit Bonus – Available in Japan and Selected Countries only!
  • 100% Bonus up to ¥25,000 with your first deposit (New customers)
  • Bonus available on your second purchase
  • EnergyCasino offers exclusive bonuses for CasinoBonusCenter visitors
  • 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 $13,186,400 in Jackpots by Games Global
  • Available in multiple languages, including English
  • Tested and certified by Casino Bonus Center · Rating: 4.4/5
  • Popularity: This offer has been claimed by 173 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.

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)
  • Bonus available on your second and third deposit
  • GambleZen Casino 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 GambleZen Casino
  • Available in multiple languages, including English
  • Tested and certified by Casino Bonus Center · Rating: 4.2/5
  • Popularity: This offer has been claimed by 152 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.

ReloadBet

Online Sports and Casino Betting · $1,000 Welcome Bonus!

Welcome offer:

100% Bonus up to

$300

Bonus on first deposit

Terms & Conditions apply ·  Play responsibly

ReloadBet

Online Sports and Casino Betting · $1,000 Welcome Bonus!

  • 100% Bonus up to $300 with your first deposit (New customers)
  • Bonus available on your second and third deposit
  • 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 $13,186,400 in Jackpots by Games Global
  • Available in multiple languages, including English
  • Tested and certified by Casino Bonus Center · Rating: 3.9/5
  • Popularity: This offer has been claimed by 140 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.

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
  • Bonus available on your second and third deposit
  • Slotastic 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 Slotastic
  • Slotastic is available in English
  • Tested and certified by Casino Bonus Center · Rating: 3.4/5
  • Popularity: This offer has been claimed by 132 visitors so far this month.
  • Game Providers: SpinLogic and Visionary iGaming

Miami Club Casino

Claim 20 free spins, plus a $4,000 bonus on your first deposit!

Sign-up Bonus:

20

Free Spins

No deposit required

Terms & Conditions apply ·  Play responsibly

Explore bonuses at Miami Club Casino

Miami Club Casino

Claim 20 free spins, plus a $4,000 bonus on your first deposit!

  • 20 Free Spins · No deposit required
  • 400% Bonus up to $4,000 with your first deposit (New customers)
  • Bonus available on your second and third deposit
  • Miami Club Casino offers exclusive bonuses for CasinoBonusCenter visitors
  • 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
  • Miami Club Casino is available in English
  • Tested and certified by Casino Bonus Center · Rating: 3.1/5
  • Popularity: This offer has been claimed by 123 visitors so far this month.
  • Game Providers: WGS Technology and DragonGaming

Gday Casino

Up to $500 in bonuses plus 50 free spins!

Welcome offer:

100% Bonus up to

$100

+ 25 Free Spins

Bonus on first deposit

Terms & Conditions apply ·  Play responsibly

Gday Casino

Up to $500 in bonuses plus 50 free spins!

  • 100% Bonus up to $100 + 25 Free Spins with your first deposit (New customers)
  • Bonus available on your second and third deposit
  • 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 Gday Casino
  • Gday Casino is available in 2 languages: English and Finnish
  • Tested and certified by Casino Bonus Center · Rating: 3.8/5
  • Popularity: This offer has been claimed by 116 visitors so far this month.
  • 112 Game Providers: Realistic Games, Big Time Gaming, Storm Gaming, Switch Studios, Leap Gaming, Spinmatic, Apollo Games, Wazdan, Neon Valley, Neko Games, Leander Games, Merkur Gaming, and others.

Top 10 Online Casino Bonuses in Japan (August 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 August 2025. Zodiac Casino, bitStarz, 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

80チャンスは億万長者になるために!

80 Free Spins

Claim up to ¥50,000 in Bonuses

Bonus of 100% up to ¥10,000 + 180 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

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

The best games, all in a safe place

Bonus of 100% up to $200 + 200 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.