I read that as "caution giraffe sex". Glad it's not that...
4th picture http://www.mangago.me/read-manga/pet_keiyaku/
Second last is this one :v
http://www.mangago.me/read-manga/sweet_inomoto_rikako/an/sweet-inomoto-rikako--chapter-6.html/3/
The last one looks like it could be one of Watanabe Asia's works. I just don't know which one since her characters kinda look the same to me.
this one is Pet Keiyaku!!
http://2.bp.blogspot.com/-G57vqqRQc1Q/UU87r_R9NzI/AAAAAAAAOAA/mYyJSptKX88/s1600/021.png
http://25.media.tumblr.com/tumblr_m2pjdri9081ru18nho1_500.jpg
http://25.media.tumblr.com/tumblr_m8929qf01S1rt17bmo1_500.jpg
https://s-media-cache-ak0.pinimg.com/736x/ea/6f/35/ea6f35408f7ee284baf72f971f6aa5e0.jpg
http://2.bp.blogspot.com/-G57vqqRQc1Q/UU87r_R9NzI/AAAAAAAAOAA/mYyJSptKX88/s1600/021.png
http://25.media.tumblr.com/tumblr_mb8g73fLAd1r0qnsro1_500.jpg
http://31.media.tumblr.com/tumblr_m035roqXTZ1rpaw7io1_500.png