Yes, trains in Osaka are extremely crowded during peak rush hours, which occur from roughly 7:30 AM to 9:00 AM and 5:30 PM to 7:00 PM on weekdays. During these times, major lines like the Midosuji Subway Line (the city's main north-south artery) and the JR Osaka Loop Line can reach high-fidelity levels of congestion where passengers are packed tightly together. However, outside of these windows, Osaka’s rail system is efficient and relatively comfortable. For a traveler in 2026, it is strongly advised to avoid these peak times if you are carrying large luggage, as maneuvering through the dense crowds in stations like Umeda or Namba can be nearly impossible. Unlike Tokyo, where some lines use "pushers" to pack people in, Osaka's crowds are slightly more manageable but still intense. If you must travel during rush hour, try to find the "Women Only" cars (marked with pink signs on the platform) if applicable, or aim for the very front or back of the train where crowds are sometimes marginally thinner.