would it be reasonable for me to take 5 AP classes during junior year? i want to take AP lit, APUSH, AP japanese, AP BC calculus, and APCSP. so far, i’ve been a good student in all of these classes.
It’s A LOT.
have you taken AP’s before? Honors classes?
What grade are you currently getting in Precalculus Honors or Calculus AB?
Are you in Honors Japanese 4?
In English 10 Honors? (Is AP Lit the regular junior class? Because often students take AP Lang junior year)
APCSP is usually fine regardless, but for better choices I’d need more details about your situation wrt the other subjects. 
I’m taking 5 APs (Chem, Lit, Art History, Gov, and Macro) , Spanish IV Honors, and dual enrollment math/electives as a senior and I’m doing fine, but I did take several APs/dual enrollment classes last year, so I already have experience with very challenging courseloads. How many APs/advanced courses are you in this year?