Lu! Laser ninja

The fifth book. It seems that in the new school year, Lu will have no time for lessons. Due to a fire, she and her mother will have to start everything from scratch, and in this new life, Lu will read her mother's diary and finally learn the truth about her past, experience a lot of doubts about first love, gain a more adult perspective on the world (especially when adults behave like children), and even unravel Grandma's secret. And also... become a big sister.