Japan 100A
I got staright A in Hayashi sensei's class. She is a really gentle and kind women, just like your imagination of a Japanese mature woman. When comparing her with Nogami sensei, I would say it really depends on what style you like.
Hayashi sensei is more diligent and caring
Nogami sensei is more casual and free-style
If you ask me to rate these 2 professors in a 100-scale
Asako Hayashi: 95/100
Nogami Yoko: 80/100
But taking Japanese with either one is doable and probably enjoyable if you do like Japanese language studying.
The homework and quizzes of Japan 100A could be a little bit overwhelming because they are really a lot. But you'll be fine.

I took Japanese 1, 2, and 3 with Hayashi- sensei.
She is an awesome professor! She has a very Japanese style mindset, having lived and worked in Tokyo for quite some time, so you definitely need to be able to maintain a level of professionalism in her class or she won't be too pleased. However, even though she seems a bit intimidating at first she is also very friendly and funny. Her class moves really fast (though I'm assuming all Japanese language classes move fast at UCLA) but you will be surprised and impressed by how much you learn. Her class has many components filled with lots of practice and it she integrates TA discussion sections so well with lectures that you are constantly having Japanese language skills drilled into your head.

Her class has lots of components (quizzes, kanji quizzes, tests, oral recordings, oral presentations, skits, sakubuns, etc) but they never take that long to complete nor are they particularly difficult to complete. Plus all of these different components simply give you more and more practice and make you feel like you truly are learning Japanese rather than doing busy work and not feeling like you're really learning a language. If you make sure you do all of your assignments on time and study for all of the quizzes and exams (ESPECIALLY kanji quizzes) it should not be that hard to get a good grade.

After taking her class I knew for sure that I wanted to minor in Japanese and I feel lucky that UCLA has such a great Japanese department right now.