Yes. A platonic friendship is possible between a guy and a girl as long as they know their limits. A close friendship between a guy and a girl is possible as long as they can get along well and getting along well means that they may have the same interests and hobbies or may even have something in common.
As long as the guy and the girl keep their distances from each other at certain times(e.g in each other room or in somewhere private) they should be able to maintain a platonic friendship. They guy and the girl may even give each other some moral support which their sex is unable to give.
For a platonic friendship to work, we have to trust that the other party in a platonic friendship doesn't think otherwise. and they may be able to pass on each other life experiences to each other and help make the world a better place. Therefore in my opinion, a platonic friendship is possible between a guy and a girl.