The story of Milk Bubbles Always Asking Why is Milk Bubbles’ School Diary. There are three small boxes in the story, pink, green, and blue. The small blue box is called Milk Bubble. It is a little boy. He is chubby like a little pumpkin and is so cute. Although he is usually dull, he can always win unexpectedly at critical moments. The small pink box is a little girl named Gaga, who is as beautiful as a flower and smart. The small green box is a little boy with spinach.