Sophomore or senior year teachers for recommendations?

I’m planning to apply EA to Harvard, and I’m going to ask teachers for letters of recommendation tomorrow (yes, I know it’s a little short notice). I have pretty good numbers-3.9 GPA, 35 ACT, and 780 on Math II (planning to take Lit on Saturday and Japanese next month). The problem is that I spent my junior year in Japan on exchange, so I don’t have junior teachers to ask for letters. I’m planning to ask the math teacher I had for acc. pre-calc and calc BC as a freshman and sophomore. She also acts as my advisor or tutor for my current math (linear algebra), and we have a good relationship so I feel good about that. I haven’t had any other teachers for more than 1 year, and I’ve only been in school for ~4 weeks so far so I don’t have great relationships with any senior teachers yet. Would it be better to send a letter from a teacher who I’ve only had for a month or one from a teacher I haven’t had for 3 years (I’d probably ask my freshman English teacher who is also my advisory teacher and the advisor for the philosophy and ethics club that I started)? I’m not sure how it would look to send a letter from a teacher from freshman year, but at the same time I’m not sure that I know any of my senior teachers well enough for them to be able to write a good letter for me. Thanks!

I would go to the teacher from freshman year. Maybe send them an email to refresh their memory (i.e. Hello Mr/Mrs X, you taught this class in this semester/year. I really enjoyed X about it. My overall grade was X…etc.) and include current information about you, like your personal essay, grades/test scores, experience, resume, what you might want to major in, things like that. Then, suggest stopping in their classroom or office to talk to them if they are willing to write you a letter of recommendation.

Check the college requirement. For instance, Stanford only accepts LORs from junior or senior teacher unless it is from an advanced level class.

Cannot one of your junior year teachers (in Japan) provide a recommendation?

I have asked my Japanese tutor (private tutoring was part of the exchange program) but I assumed that she would count as an other recommender because she isn’t a teacher at a school. So I’ll have other recommendations from her and my exchange counselor, who will write me a very good one, but neither of them will count as teachers.