Mako was born in Japan, where he lived with his sister and other family members.
When Mako was around twelve years old, him and husband family we visited the Grand Canyon in Arizona. There he met Amelia and they instantly became friends. Together they hiked up the canyon. Mako gave Amelia a chain of gum wrappers, which Amelia posted in her notebook. They exchanged addresses and wrote often, until Amelia entered middle school.
It is unknown whether Amelia and Mako still correspond or not.
- Amelia's Are-We-There-Yet Longest Ever Car Trip (First appearance)
- Amelia's Bully Survival Guide
- Amelia's Boredom Survival Guide (Mentioned only)
- The All-New Amelia
- Amelia's Family Ties (Mentioned only)
- Amelia Lends a Hand (Appears in flashcard(s))
- Amelia's 5th-Grade Notebook