I think educators should look good all the time. If I'm a teacher this would be my look and variations of it.
It's sensible to invest in a smart looking button down shirt. With ukay nowadays, all you need is patience to trawl a mountain of dusty clothing in the thrift stores to find that perfect fit for you. The shirt I'm wearing is a Y's Yohji Yamamoto and it cost me a dollar for it. Ditto with the waistcoat. Oh, and the Calvin Klein jeans, too. That's $3 for 3 pieces. The Topman belt was more expensive to buy. Hahaha!
My trusty old Muji sneakers looks proper for the pinstripe jeans. Even the bottom two pieces are casual staples I still look respectable when paired with a proper top.
And for a little quirky inspiration, the Tokyo map hanky given by Kiks.