My rRoom. My Room

I use an air conditioner in my room. I use an air conditioner in my room.

I use an air conditioner in my room because the weather in Japan is hot right now. I use an air conditioner in my room because the weather in Japan is hot right now.

or: The weather in Japan is hot right now, so I use an air conditioner in my room. It is also common to abbreviate air conditioner as AC.

I useMy room has an air conditioner my room. My room has an air conditioner.

Japan is hot right now. Japan is hot right now.

Since this connects to the previous sentence you can connect these for better flow and saying something like: "Japan is hot right now, so I use an air conditioner in my room."

Japan is hot now.(combined with previous) (combined with previous)

Japan is hot right now. Japan is hot right now.

I have a lot of idols goods in my room. I have a lot of idol goods in my room.

I have a lot of idols goods merch in my room. I have a lot of idol merch in my room.

I have a lot of idols goods in my room. I have a lot of idol goods in my room.

My treasure! My treasure!

You can combine this at the end of the previous sentence for better flow: "I have a lot of idol goods in my room and they are my treasure!"

My treasures! My treasures!