Everyone meets in Osaka on the same evening. Group B (Sydney) lands at 19:50 and Group A (Cochin) lands at 21:35, one hour and forty-five minutes apart, so we can all be at the first hotel the same night. Thursday 8 October is the clean backup date if the 6th does not work.
Target arrival Tuesday 6 October 2026. All times local to each airport.
Shorter-layover alternative: SQ537 leaves Kochi at 01:22 and reaches Singapore about 08:45, for a roughly 5.5 hour connection onto the same SQ622.
Jetstar runs this nonstop about three days a week (a Tuesday, Thursday, Saturday pattern). If the date shifts off those days, the fallback is a nonstop to Tokyo plus the shinkansen down to Osaka.
Open-jaw: we fly home from Tokyo Haneda (HND) on the morning of Tuesday 20 October. Group A connects through Singapore; Group B is a Qantas nonstop. Both leave Haneda early, so plan the last night close to the airport or allow time for the trip out.
Cheapest nonstop on this route. Jetstar only flies Tokyo to Sydney with a stop, for a bit less, if you would trade the nonstop for a cheaper fare.