Battle Cats Wiki
You know the old story: A young and ambitious fish, learning the ways of love! Join this month's special unit, the Koi Cat Carp A. Diem, as he dares to dream of romance and success, while fending off the forces of cynicism embodied in mean ol' Samurai Doggy.

PONOS' announcement

Love is Sickness (コイの五月病, Koi no Gogatsubyō, Koi May Disease) is the May event in The Battle Cats.


During this event, a new enemy unit appears: Samurai Doggy! And if any player clears any of the stages during this event, a new cat unit only available during this event: Koi Cat, can be unlocked by chance. The further you progress through the levels, the higher your chances of unlocking the cat unit increase. The player can get the unit with a 100% chance in any of the stages using a Treasure Radar, which can be purchased at any time in the Shop Menu.

  • 2♛ difficulty for this event multiplies enemy strength magnifications by 150%.
  • 3♛ difficulty for this event multiplies enemy strength magnifications by 200%.
  • 4♛ difficulty for this event multiplies enemy strength magnifications by 300% and only allows Special Cats and Rare Cats to be deployed.


English Version Japanese Version Translation Energy Cost
Stage 1 Liking Love コイにつかれて (Koi ni Tsukarete) Stuck in the Koi 30 EnergyIcon.png
Stage 2 No More Duckface! 満腹!アヒルぐち (Manpuku! Ahiru Guchi) Full Stomach! Duck Mouth 50 EnergyIcon.png
Stage 3 Read but No Reply 恐怖!既読放置 (Kyōfu!Sunde dú Hōchi) Fearful! Left on Read 75 EnergyIcon.png
Stage 4 Online Dating! 最高!ネトゲデート (Saikō !Netogedēto) The Best! Netgear Dating 80 EnergyIcon.png
Stage 5 Blocked on FB! 衝撃!ラインブロック (Shōgeki!Rain Burokku) Impact! Line Block 90 EnergyIcon.png
Stage 6 Work or Me! 選択!仕事とアタシ (Sentaku!Shigoto to Atashi) Choice! Work and Me 95 EnergyIcon.png
Stage 7 Let's Just Be Friends 告白!友達に戻ろう (Kokuhaku!Tomodachi ni Modorō) Confession! Back to Friends 100 EnergyIcon.png
Stage 8 Never Give Up! それでも君にコイしてる! (Soredemo Kimi ni Koi Shiteru!) I'm Still Koi for You! 110 EnergyIcon.png

First Appearances

English Version

  • May 1st, 2015 to June 1st, 2015

Japanese Version

  • May 2nd, 2014 to May 31th, 2014



  • The stage makes little sense in English due to its strong reliance on a Japanese national holiday, its associated traditions and a Japanese language pun.
  • The 5th of May in Japan is Children's Day, and part of the nation's Golden Week holiday celebrations.
  • Koi Cat is indicative of the Koinobori flags/kites/windsocks patterned to resemble koi (carp fish) that are put on display in prominent locations during the festivities. Colourful pinwheels are also associated with children.
  • The Samurai Doggy enemy is indicative of the samurai-helmet wearing Kintaro dolls also put on display.
  • Koi in turn is a homophone in Japanese, meaning both 'carp' and 'love', hence the romantic themes.
  • The quote on the banner, "With ambitions higher than any rooftop!", may be a reference to the first line in a japanese song about koinobori, やねよりたかいこいのぼり (yaneyoritakaikoinobori), meaning "koinobori that is higher than the rooftop"


Monthly Events
Happy New Year? No Happy HolidaysHoliday Diet FailNo More ResolutionsJust One More DrinkAfter After PartyForgot the CountdownBlackoutHangover
Another New Year Chores UnendingUnknown RelativesI Hope It's an UberDifferent from the AdJust What I Wanted
Ritual Happiness Angelic DevilDracula Donates BloodMy Pet WerewolfSunbathing MummiesSoul LeasingLucifer Likes to SmileZombies being HealthyHumans are Scarier
Ritual Confusion Hang onto HappinessSilent FamilyEat Happy SushiExpired JoySins and Blessings
Bears be Bare Bear GrillsBearly DressedWith a Ton of PaddingBees with EarsArming BearsGoing BipolarFighting BearhandedCan't Bear Anymore
Bears Be Back Hibernation's End2 Much 2 BearGrizzled VeteransWhat We Do In The WoodsBear in Mind
Teacher! It's Spring! Cat School MusicalI can feel itThe CatbookP.S Cat Loves You100 Cat DatesLamentI L ULet's Start Over
Spring for Sensei Faculty ChangeYou in a Petri DishDangerous EquationsLitmus of LoveU + Me = Photosynthesis
Love is Sickness Liking LoveNo More Duckface!Read but No ReplyOnline Dating!Blocked on FB!Work or Me!Let's Just Be FriendsNever Give Up!
Lovesick Again Pain of LoveNo Right SwipesArranged MarriageBiological HourglassSettling Down
The Forbidden Bride Wedding ToilsSending a FriendBGM is "Macarena"Bouquet Finds WaterFamily Drama WoesMistook Bride's NameEx says I object...No, I Do Not
Forbidden Bride Pt II The Ex AppearsAwkward S.O.Family FeudingDouble ProposalShow Me The Stars
Never Summer! Glutton Next DoorSummer Already?Something About CatsSummertime SmoothieStarving in SummerBoy Meats GirlSandbags on the CapeRight here, right meow
Never Not Summer! Leak YearCats of YesterdayHeat Wave BluesLazy TomorrowYoung Nyan
Ghostly Houseguests Dad's back to haunt usBut we're on vacationCan't pass thru walls?Just hit the skies!Wasting inheritanceHiring fake mournersGrave is just plastic...I'm not here anymore.
Ghostly Strangers Dad's Back to HeavenLong Line at CerberusCharon's OverbookedStill on VacationSee You Next Year
Old Guys About Town Dawn JoggersDay Job = BoxersEscaping the Home300 Years ProbationBearhanded BrawlerTrophy WivesLiving the DreamWife Still the Boss
Old Guys in the City Night ShuffleboardTwilight Wandering5 Secret FamiliesTwo Years CursedThe Wife Still Wins
Autumn = Sports Day! Gotta Warm Up FirstAwkward EntranceDad, No Videos!The Sack RaceFaster BarefootEgg-Glue-SpoonChicken RunEveryone Wins
Autumn = Sports Day! (old version, BCJP only) Athletic MeetAnti HalloweenWinning and Losing
Sports Night Inviting Cemetary2 Bodies, 0 LegsGrave BouquetFallen PriestHours 'Til Morning
Loving Labour Weeklong MeetingsCo-workers don't workStress Relief StressJobs in Jobs SecurityPay without LeaveValue of Last Minute
Worker's Revolution Premium FridayTotal ProfessionalCORE TIMEMaternity Leave ForeverLate Nite Shake-Up
Jingle Cat Bell That NightThat SongWarm StewCat & SnowPart Time SantaSanta or Satan!?Santa is on SalaryHappy Merry X-mas
Christmas in Space That's Not Santa...Jingle HellNot-so-Silent NightPresent HuntersCosmic Xmas