Otaku no Musume-san

I started reading this one a whim, but it has turned out to be one of the better series I have read. It starts about a girl looking her father. She finds him, but to her dismay he is a hardcore otaku. Kanau, the aforementioned Daughter of an Otaku, was temporarily abandoned by her mother who ran off due to a severe debt to a loan shark. She was conceived back when her mother and father were still in high school. When Kanau's mother disappeared from high school, her father fell into a deep depression and was only brought out of it by dating sims. Kanau is now age nine, and her father must suddenly accept that he had a daughter with his long-lost love. Throw in an entire apartment of otaku, doujin authors, and a hardcore lolicon, all run by a mature looking landlady.

The series sounds like a rather cliché gag series, but underneath is a surprisingly deep and well thought out story and cast of characters. Kanau's mother appears in the story from time to time, and there is definitely a lot of secrecy surrounding her backstory. Each of the side characters gets a number of plot arcs, and they're actually very well fleshed out characters. They make mistakes, they have their own secrets, they grow and develop as people (even the minor ones!). The main characters, Kanau and her father, grow a great deal over time. There are fights and drama, but also a lot of compromise. Kanau overcomes her prejudice about otaku and their lifestyle, her father is forced to become a responsible parent, and everything in between.

The series is heartwarming, full of twists you didn't expect but make complete sense in retrospect, and loaded to the brim with various anime, manga, and game references (Eva, Maison Ikkoku, Nanoha, Street Fighter, Fate/Stay Night, etc.). Most striking to me was the characters came off as a real people (if a little exaggerated for humor) who really change from chapter to chapter.