PeroPero often gets updated.
I will try to past what new cards and changes each update brings.

September the 16th 2015

The following 3 new cards are added to N-Gacha:
Mari Yamaguchi(N-B)
Fumi Anneu(R-B)
Hinako Toyoshima(SR-B)
The last two cards is also added to R-Gacha. These cards are not added to SR-Gacha.

Kurito gets the following 3 new card:
Kiyura Miono(N-B)
Nina(R-B)
Matoi Akino(SR-B)
The 3 limited cards Kurito had before have been removed from the game.

Reika Arita(N-M) an old slayer card was also added to N-Gacha.

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September the 18th 2015

E-Gacha are for sell again.
The follow new slayers cards have been added to E-Gacha:
Azusa Yumeno(N-M)
Rurian Hakuto(R-B)
Kashisu Kokuto(SR-S)

N-Gacha gets:
Azusa Yumeno(N-M)

The following 2 cards which was slayer cards in 3th event have been returned to the E-Gacha:
Hayami Terashima(R-S)
Souko Yukawa(SR-M)

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September the 21th 2015

The 6th event start. Lightning boss event.
The following 3 girls are added as rewards for 6th event:
Rewards
Kasumi Oshiya(R-B): reward for 100K EP.
Akira Shiranui(SR-B) Reward 100 super boss kills.
Ami Komodo(SR-B) Reward top 1000.

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September the 28th 2015

The 6th event 2nd week.

3 new cards are added to E-Gacha as slayer girls:
Wako Amagito(N-B)
Matsuri Sato(R-S)
Souko Yukawa(SR-B)

N-Gacha gets:
Wako Amagito(N-B)

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October the 5th 2015

6th event ends.
E-Gacha are removed.

SR-Gacha get the following new cards:
Himeka Muroran(SR-B)
Mizumi Nakai(SR-B)
Tamami Ikuta(SR-B)

SR-Gacha now have 20 R and 17 SR.
R-Gacha now have 21 R and 15 SR.
N-Gacha now have 30N, 21 R and 15 SR.

N- and R- Gacha have the following cards that don't exist in SR-Gacha.
Fumi Anneu(R-B)
Hinako Toyoshima(SR-B)

The 3 new Players can pick in next event
1) Kusomi Ogura(?-S)
2) Ayame Nanase(?-S)
3) Saya Sonoda(?-S)

New card with no known way to obtain :
Yukimi Sakuraishi(R-B)

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All the girls that can be obtained from bonus stage atm:




SR-Wild1, SR-Wild3 and SR-Wild5 can also be obtained from bonus stage.
This list is basses on 1000s of spins at bonus stage but if I am missing any girls that can be obtained form bonus stage please write.