Undecided

Oh I totally didn't expect this to happen!
I have already booked the air tickets to Taiwan in December.
God knows our lecturer selected our group to go to Osaka for a presentation!
The dates clash, I can't change my SQ ticket to Taipei.
I can't book a direct flight from Japan to Taipei cause it's damn ex!
The only way is to route through HongKong.
Nonetheless, I have other things to worry about i.e. my siblings who are travelling with me
Though they are old enough to take care of themselves,
One can't help worry
Now I am really undecided.
One of my group mates might give up.
If he gives up, then I need not fret cause it's either we go as a group or we don't go
If he doesn't give up, then the burden is on me or rather the decision lies in my hands
Perhaps I could talk to my lecturer about the SIN-OSAKA-TAIPEI-SIN leg
Nonetheless, it's gonna be like 10 over hours of flight all the time.
I seriously wonder if it's worth all the trouble?
Or I should just go to Taipei and not be bothered about this
At least Mom is supportive of me heading to Japan and them to Taipei first.
Some assurance helps. :)