Breakdown of tomodachi wa kijimihon no shitsukan o kurabete bakari iru.
Questions & Answers about tomodachi wa kijimihon no shitsukan o kurabete bakari iru.
は marks 友達 as the topic: as for my friend / my friend, ...
That means the sentence is talking about what the friend is doing, rather than introducing the friend as new information.
- 友達は = As for my friend, ...
- 友達が would sound more like It is my friend who... or would introduce the subject more directly.
So は feels very natural here if the friend is already part of the conversation.
