Oh-ya-su-mi-na-sai
Here's a breakdown:
* Oh: Like the English word "oh"
* ya: Like the "ya" in "yard"
* su: Like the "su" in "suit"
* mi: Like the "mi" in "might"
* na: Like the "na" in "nap"
* sai: Like the "say" in "say"
It's important to note that the "i" at the end of "na" is very short and almost silent.
Let me know if you'd like to hear it pronounced! I can try to find an audio clip for you.