Nadeshiko is a cool concept: a capsule hotel just for women upgraded with ryokan-style touches, for example guests get to wear colourful yukata and zori sandals. Rates can rise by up to 40% on peak days or weekends, which honestly is a lot for what you get. Note that there is no elevator and the lockers provided are too small for suitcases.
Nadeshiko Hotel
Shibuya & Shimo-Kitazawa