無口系萌え[mukuchikei-moe];
無口[mukuchi] means not to speak at all.
A person who doesn’t talk much.. is 無口系[mukuchikei].
系'[kei] means a type of person here.
Also, if she is so cool rather than cold? And what if such an emotionless girl fawns upon you when she bursts into tears? Yes, she would be a type of クーデレ. クー[coo] derives from cool, and デレ[dere] stems from デレデレ[dere dere] which has a nuance of being so sweet. Speaking of クーデレ girls, I can think of Rei Ayanami [Evangelion], Himoo Yuina [Toki meki memorial], or Mai Kawasumi[Kanon]. If you look at any bishoujo anime carefully, you might find this type of girl.

Air - Hime


Akane Maniax - Kei


Aria co. - Alice & Athena


Ayakashi - Eimu


Azumanga Daioh -Sakaki-san


Baccano - Ennis


Bakuretsu tenshi - Joe


Black Lagoon - Maria


BLAME - Cibo


Bleeech - Nemu


Bokuraga Ita - Yuri


Busou Renkin - Tokiko


Canvas2 -


Chrno Crusade - Dark Rossette


cLANNAD - Kotomi


Code Geass - C.C.


Claymore - Claire


Da Capo II - Anzu


Darker than Black - Yin


DearS - Ren


Detective Conan - Ai


Doujin Works - tsu.uri

EL Cazardor - Ellis


Elemental Gerade - Ren


Elefen Lied - Lucy


Ergo Proxy - Riel


Fate Stay/ Night - Rider


Full Metal Panic TSR - Thestarossa


Galaxy Angel - Vanille & Chitose ithk l0l..


Gantz - Reika


Genshiken - Ogiue


Ginban kaleido - Tazuna & Ria


Girls Bravo - Koyomi


Godannar - Lou


Goshuushou-sama Ninomiya-kun - Shinobu


Gunparade March - Mai


Gunslinger Girl - Angelica


GunxSword - Tasalina


H2O Footprint in the sand - Hayami


Haibane Renmai - Reki


HanTsuki - Rika


Heroic Age - Yuti


Higurashi no Naku Koroni - Rika


Hitohira - Mugi


Hitsuji no Uta - Yaegashi


Hunter x Hunter - Shizuku


Ichigo 100% - Tohjou


Ichigo mashimaro - Nobue


ikkitousen - Shimei


Interlude - Watatsuki


Iriya no Sora - Iriya


Jigoku shoujo - Ai


Jinki Extend - Rui


Kamichu -


Kannaduki no Miko - Chikane


Kara no Kyoukai - Kirie


Karin - Anju


katekyou hitman - Dokuro-chan


Kaze no Stigma - Lupis


Keitai shoujo - Rin


kekkaishi - Aihi


Kiddy Grade - Eclair


Kimiga aruji de hitsuji ga orede - Shinra


Kimikiss - Eriko


Kino no Tabi - Kino


Kodomo no Jikan - Kuro


Koi Kaze - Nanoka


Koi Koi 7 - Gantai-chan


Kujibiki Unbalance - Ritsuko


Kyou no 5-2 - Aihara


Kyoshiro to Towa no Sora - Kaon


Magical Girl Lyrical Nanoha strikerS - Lutecia


Midori no Hibi - midori


Mahoroma - Rin


Mamoru-kun ni Megami no Shukufuku wo - Elemenzia


Minami-ke - chiaki


Moekko Company - Inoue-sensei l0l


Murder Princess - alitta


Mushi Uta - Shieka


Myself;Yourself - Nanaka


Nanatsuiro Drop - Nona


Narutaru - Akira


Naruto - Hinata


Negima - Konoka & Ayase


Negima - Chachamaru & Evangeline


Negima - Rainy Day


One Piece - Robin


Petopeto-san - Kuguru


Popotan - Mea


Prism Ark - Tetsuya


Rahxephon - Reika


Raki Suta - Minami


Raimuiro senkintan - Rinzu


Ray the Animation - Ray


Requim from the Darkness - Gin-san


Rosario + Vampire - Shirayuki


Rozen maiden - 7th Doll


Saint October - misaki


Sayonara Zetsubou-sensei - Abiru


School Days - Kiyora


School Rumble - Imouto-san


Serial expiriment Lain - Iwakura


Shaman King - Iron Maiden Jeanne


Shakugan no shana - Vilhelmina


Shakugan no shana - phyles


Shakugan no Shana -Hekatei


Shigofumi - Fumika


Shinigami no Balad - Momo


Shining Tear x Wind - Blane


Shion no oh - shion


shuffle - Primula


Sketchbook full colorS - Kajiwara


Soukou no strain - Emily


Soul Link - Yuu


Spiral - Madoka


Tonagura - Rin


Tsukiyomi Moon Phase - Arte


Tsuyokiss - Nagomiya


Utawarerumono - Turka


Venus Versus Virus - Lucia


xxxHolic - Yuko


Yamato Nadeshiko Shich Henge - Nakahara Sunako


Yamito boushito hon no tabi - Hazuki


Group :D