Extend Graduation to Study Abroad?

Hello everyone! I'm in a bit of a conflicting situation and was hoping to get some perspectives from those of you with more experience than me.

To provide some backstory on myself, I'm a North American college student who has taken multiple extended holidays to Japan. My Japanese is about N5, and my goal is to move to Japan to live and work after graduation.

I'm a Computer Science major and I'm about to enter my senior year. This is the worst time ever to do this, but I've been learning more about scholarships for studying abroad and I'm rapidly beginning to regret not seriously considering it sooner.

I've been thinking about double majoring in Japanese, which would extend my graduation by about a year or more, to study abroad and try to improve my language skills into something much more viable by the time I graduate. At the very least, I want to minor in Japanese.

I've received conflicting opinions from a professor who has told me that I should focus solely on improving my programming skills (and opportunities on campus, like being a TA) and that Japanese would only be a distraction, but I'm not sure if they fully understand how strongly I want to live in Japan.

Just hoping to get some perspective and opinions! Does it even really make a difference at all? Would I best off just finishing my computer science degree and trying to find an English speaking job until my Japanese improves? Would it look better to study in Japan and have better Japanese or to have been a TA at my university? I greatly appreciate any advice in advance. Thank you!