Oh right, what is a tsundere? A tsundere is a Japanese term to describe a person who is initially cold and even hostile towards another person before gradually showing their warm side over time. Based on this trait alone, tsundere often has a storyline where they have to live alone because they don't really clique with the society. It's the Happy Soloist's cup of tea for anime. Some of good anime that she has watched for her love for tsundere are: 

1. Toradora

Aisaka Taiga is a definitely tsundere and guess what, she is living alone too. A tsundere who is living alone, really the Happy Soloist's perfect cup of tea. #ultimateotakumode

2. Hayate no Gotoku

The rich ojou-sama, Sanzenin Nagi, may live with her butler and maid but her tsundere cuteness toward her butler is so cute, it melts the Happy Soloist's heart. #okayamitoomuch

3. Lucky Star

Kagami Hiiragi is my favourite character other than Konata from Lucky Star. And she is a moe tsundere with purple twintail hair. Ultimate cuteness in the anime world. 

4. Fate Stay Night

Another favourite character of the Happy Soloist, a strong tsundere who can do magic. 

5. Shakugan no Shana

And if the Happy Soloist's above point is not enough, how about a tsundere who love eating melon pan and good with fire? 

Despite all the above tsundere characters, the above anime are really fun to watch. You may also fall in love with the girls' characters too after you watch them. Watching anime can be a one of the thing to do when you cannot sleep. For other ideas, you can read 5 Things to Do When You Cannot Sleep at Night.