What is a good anime to watch for a 12 year old?

Probably Death Note, Fullmetal Alchemist, One Piece, Inuyasha, Durarara, Lucky Star, Fairy Tail, Angel Beats, Hetalia, Dragon Ball, Black Butler, Bleach, Soul Eater, Naruto, and maybe Code Geass

It really depends on her preferences. Like with genres and stuff. Here are some ideas, though:

- Nichijou

- Free!

- Soul Eater

- Toradora

- Ouran High School Host Club

- Angel Beats

- K-On!

- Madoka Magica

- Princess Jellyfish

- Uta no Prince Sama

- Tsuritama

there are many animes that would appeal to a 12 year old but, many depend if the 12 year old is a new anime lover or a common anime lover; i would suggest Naruto, Sailor Moon, Fairy tail, or Hunter x hunter

You should probably go for shows where the 12 year old girls are the target audience, for the most part.

I don't know your sister, of course, but here is what I would recommend to people of that demographic:

-Any magical girl anime (Shugo Chara!, Sailor Moon, Pretty Cure, etc.)
-Fullmetal Alchemist
-Detective Conan
-Any of the Big 3 (Bleach, Naruto, One Piece)
-Ouran High School Host Club
-Rozen Maiden
-K-on!
-Angel Beats
-AnoHana
-Inyuyasha


Really, it all boils down to what you think your sister would enjoy the most.

Have her watch all of DRAGON BALL Z

One piece is a good one

Rurouni Kenshin can be a good one.

I recommend Cardfight Vanguard and make her engaged into it. If not, then Lucky Star should be appropriate.

Shugo chara! definitely

Hmmm...I think my answer is rather a "12 year olds in general" kind of answer.

- Moshidora - Sport / Drama / Slice of Life (Shounen)

- Disgaea - Fantasy / Action / Comedy (Both)

- The Devil is a Part-Timer - Comedy / Action / Fantasy (Shounen)

- Full Moon wo Sagashite - Romance / Drama / Comedy (Shoujo)

- Bleach - Action / Supernatural / Comedy (Shounen)

- Sailor Moon - Romance / Magical Girl (Shoujo)

- Amnesia ( Despite episode 9, the anime is actually rated as 13+) - Mystery / Drama / Romance (Shoujo)

- Cute High Earth Defense Club LOVE - Magical Boy / Comedy / School (Both, I guess)

- Bakugan - Adventure / Gaming / Fantasy (Shounen)

- Beyblade - Sports / Adventure / Action (Shounen)

- Metal Fight Beyblade - Same as Beyblade (Shounen)

- D.N.Angel - Romance / Action / Fantasy (Shoujo)

- Fruits Basket - Romance / Drama / Comedy (Shoujo)

- Free! - Slice of Life / Sports / Comedy (Both)

- Galaxy Angel - Comedy (The manga also has Romance) (Both)

- Ouran High School Host Club - Comedy / Romance / Harem (Shoujo)

- School Rumble - Comedy / Romance / School (Shounen)

- Shugo Chara! - Comedy / School / Magical Girl/Boy (Shoujo)

- Sonic X - Adventure / Comedy / Sci-Fi (Shounen)

- Tokyo Mew Mew - Magical Girl / Romance / Supernatural (Shoujo)

- Uta No Prince-sama - Music / Harem / Comedy (Shoujo) (Picture)

- Yu-Gi-Oh series - Gaming / Action / Fantasy (Shounen)

For her...Maybe UtaPri, The Devil is a Part-Timer, School Rumble, Fruits Basket and Ouran High School Host Club.

Assassination classroom
It's about a class trying to assassinate an octopus like alien with rubber knives and guns with pink tiny balls lol