Personalized Kawaii Octopus Grandpa's Sweetheart T-Shirt. Kawaii Octopus Grandpa's Sweetheart - the perfect gift for your octopus-loving grandpa! This cute and kawaii design is sure to make him smile, and it's the perfect way to show how much you love him. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.