Hi Jeab san,
If you start thinking about trip to Japan, please think about the followings.
(1) You travel alone & Stay at same room with me & Travel itinerary is arranged by me.
If you want to travel to Japan as cheaper as possible, I'll arrange the travel for you. I'll take you somewhere where I have been to before. But I am not professional. So I am not sure whether or not you can enjoy the trip. I cannot guarantee anything to you. And if you travel alone, I'll have to take annual paid leave to take care of you while you are in Japan. And It is better not to tell about that trip to our coworkers and our family because they would doubt our relationship. We have to keep silence not to let them worry about anything. We might feel some guilty as you said. As for this trip, you just pay only flight ticket for round trip. I'll pay others. I think this is the cheapest proposal. And I can promise that I won't do anything to you. I think it is very important for you and me in order to keep good relationship as a close friend.
(2)You travel alone & Stay at different room with me & Travel itinerary is arranged by me.
Almost contents are same as above (1)
But in addition to flight tickets and I will ask you to pay your hotel room fee. I’ll pay others. You can sleep without any worry. 55555
(3)You travel with friends & Stay at different hotel & Travel itinerary is arranged by me.
I can take care of you and your friends. You might be able to be more enjoyable than travel alone. But I cannot guarantee anything to you and your friends. In this case, I don’t pay anything for you and your friends. You and your friend pay anything while you & your friend stay in Japan. In that case, I can tell about this trip to my family.
(4)You travel (with friends) arranged by travel agency
If you buy travel package tour at travel agency in Bangkok, you might be more enjoyable than travel arranged by me. Because travel agency is professional. They have know-how to let traveler enjoy. If there is free time in itinerary, I might be able to meet you (& friends) to take care of you (and your friends.) In that case I take paid leave for the only date when you have free time.
I think that the travel cost: (1) < (2) < (4) < (3)
If you really start thinking about travel to Japan, please choose one choice from above proposals.
After choosing one proposal, we’ll be able to go next step. (I'll ask you what you want to do)
I look forward to hearing from you.
If you have questions, please let me know.