If you are in a higher technical position, you do not have to move to Project Manager.
If you are in a low tech position, Project Manager is a way to go to make you fell more responsible.
To be a good project manager, you need:
-- Good communication skill: recording the meeting minute, summarize the action item, and watch the date for the delivery
-- Know many concepts of many aspect of the field you are working on;
-- Like to do documentation.
Many companies need project manager, specially in the large company.
If you like it, go do it.
小丸子-- good name, you muct know some Nihongo.
Thanks!