Can I wear short sleeves in the summer?

Only if you are participating in the 'Cool Biz' initiative. Otherwise, stick to long-sleeved shirts, even in the heat.

Are tattoos an issue?

Yes. Keep tattoos completely covered at all times in a business setting.

Yes, unless you are strictly within the 'Cool Biz' period or have been explicitly told by your hosts that business casual is acceptable.

Business Attire for Japan: A Seasonal Guide

In Japan, business dress is conservative, formal, and tailored. You should always aim to look polished, prioritizing dark-toned suits, crisp shirts, and closed-toe footwear regardless of the season.

Adopt the 'Cool Biz' and 'Warm Biz' standards. From June to September, many offices participate in 'Cool Biz,' where jackets and ties are discouraged to save energy. Conversely, 'Warm Biz' in winter encourages layering; however, keep a high-quality suit jacket accessible in your bag for formal meetings.
Master the art of layering. Japanese buildings are heavily climate-controlled. Use thin, high-quality thermal under-layers in winter and breathable, moisture-wicking undershirts in summer to maintain a professional appearance without overheating or freezing.
Prioritize footwear etiquette. You will frequently remove your shoes at restaurants and certain meeting rooms. Ensure your socks are in perfect condition (no holes) and that your shoes are clean, well-polished, and easy to slip on and off.
Stick to a muted color palette. Keep colors to navy, charcoal gray, or black. Avoid loud patterns, flashy accessories, or bright ties. Your goal is to blend in, not stand out.

Can I wear short sleeves in the summer?: Only if you are participating in the 'Cool Biz' initiative. Otherwise, stick to long-sleeved shirts, even in the heat.
Are tattoos an issue?: Yes. Keep tattoos completely covered at all times in a business setting.
Do I need a tie?: Yes, unless you are strictly within the 'Cool Biz' period or have been explicitly told by your hosts that business casual is acceptable.