Personalized Kawaii Pencil Case 100 Days Smarter Youth T-Shirt. Youth T-Shirt - White with funny kawaii cartoon pencil case with eyeglasses and school supplies (pencils scissors, ruler) says I'm 100 Days Smarter. Cute 100 Days of School gift. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.