I'm not sure what context you have to be asking that question, so I'm going to answer with things you may also know already to flesh out the basic answer which is: no.

There are two major houses involved in what was known as 'The Cousin's War' and is referred to in modern times as 'the War of the Roses': York and Lancaster.

Richard II was deposed by Henry IV, Henry V came to the throne, Henry VII came to the throne, Edward IV deposed him, Richard III [eventually] came to the throne, Henry VII deposed him.

All of those Henrys are Lancastrian, Richard III and Edward IV are Yorkist.

Margaret Beaufort, mother of Henry VII, spent time in Edward IV's court. Henry VII spent his childhood more or less as a ward of his uncle Jaspar Tudor and for a time the Yorkist William Herbert. He eventually fled to Brittany after Edward IV reclaimed the throne. It isn't clear if Henry VII and Richard III met during this time, but he certainly didn't see Henry VII again if ever until the Bottle of Bosworth.

Richard III nearly killed Henry VII himself but was felled during his approach.

Given that they were both fighting for the same throne and had had little to no interaction prior to their life-or-death throne fight, they were not friends.