When you move forward,someone is in your way.
You can say”sumimasen”「すみません」
If someone bumped you,the person will say “sumimasen”.
Please reply”Ie”「いえ」
If you want to ask something to cabin attendant,say
“ano,sumimasen”
CA will answer”Hai”
“******,kudasai”–you can put the word that you want for example ear phone,blanket,oshibori=wet tissue,pirrow,etc
If you want to leave your seat and you seat is not aisle,
“sumimasen,(chotto,iidesu-ka?)”