Night Shift Nurses 1 = 11 (+ the .5 episodes) episodes
2 = I think 3 or 4 episodes
3 = 3 episodes
plus you got, Nanase Ren, Kazama Mana and Kotomi Ai
oh and please don't forget that the Night Shift Nurses series are NOT for the faint hearted
Cool Devices has 11 episode (though different...