I've read this chapter several times across many re-reads of the series. And It only just occurred to me that the time frame of this chapter doesn't make a lot of sense.
- Kiyomaro makes Vulcan for Gash before school
- before Kyomaro leaves Gash announces his intentions to go to the park with Vulcan
- Gash goes to the park, meets Kolulu, and has a short conversation with her
- Shiori gets out of school and arrives at the park to pick up Kolulu
So either Gash and Kolulu were playing at the same park for like 6 hours before they noticed each other or Gash got
majorly sidetracked before making it to the park.