The Osaka Tourist Megalist 1.0

Sightseeing/Exploring:
1. Osaka castle: https://goo.gl/maps/r5fzHyKCBSM2. Take the JR train to Osakajokoen station (https://goo.gl/maps/kYg9afhLXik)
2. Osaka aquarium: https://goo.gl/maps/5fhWVawES192. Take the monorail to Osakako station (https://goo.gl/maps/3aKs3DCZdaP2)
3. Explore the underground city of Osaka, starting from the station (https://goo.gl/maps/StKUqVdJNu12). Super easy to get lost, super fun because you get lost. Requires time.
4. Hike a trail to see the nunobiki falls (https://goo.gl/maps/njb4RX2aBn52). Around 30-45 minutes by train from JR Osaka (always take the rapid or super rapid), so allocate your time. Extremely close to Sannomiya.
5. Kyoto is a rock's throw away (metaphorically. it'll still take you 50-60 minutes by train), but the sightseeing and food is worth it if you have the time. Try kiyomizudera (https://goo.gl/maps/cJkSEiwwonr) or kinkakuji (https://goo.gl/maps/1XuWBAeeYt92) for sightseeing.

Shopping:
1. Take the subway (midosuji line) down to shinsaibashi and walk up and down the line of stores (shoutengai, from https://goo.gl/maps/Vhs14N3jXtP2 to https://goo.gl/maps/4aFjiSjv8t62). You can find literally anything here. Explore the side streets to find fun stuff. DEFINITELY DO THIS. Also has some great food places, especially around do-tombori (check food #1)
2. Anywhere and everywhere around HEP FIVE (https://goo.gl/maps/ncfbGW3RoK22). They sell a ton of stuff around that area, especially near the station.
3. Grand Front is a relatively new place that opened up (https://goo.gl/maps/fPVxk9uKF792) back in 2013. A bit more high end.
4. Again, the underground city has a ton of stuff, from clothes to sports shops to restaurants. Check it out if you have the time.
5. If you're not averse to leaving Osaka, you take take a ~30 min JR train ride down to Sannomiya (https://goo.gl/maps/HU7NinJZEZs). Walk along center-gai (starts at https://goo.gl/maps/UL3Z3txQAF52) to find everything. Sannomiya is also great for exploring, especially if you walk up the mountain a bit.
6. I put this one last since I've explored it the least, but give Namba Parks a try (https://goo.gl/maps/2z35q6fKe5u). From what I remember, I think it's higher end stuff, but they were renovating it when I left, so who knows.

Food (Note: my recommendations for food are mostly areas instead of individual restaurants, since all the great ones tend to crowd together in the same places):
1. Anywhere along Do-tombori. I recommend Mizuno (1-4-15 Dotonbori, Chuo-ku, Osaka), but it might be crowded since it's pretty popular. Basically required to do if you're visiting Osaka.
2. The more you explore, the better places you can find. I recommend walking around the basement of umeda station (https://goo.gl/maps/14Ams72BV362) and picking a store there.
3. Sannomiya strikes again, if you don't mind the train ride. It has my favorite okonomiyaki restaurant (https://goo.gl/maps/beW3E153eqv). Quality assured.

Rivers (with nice riverbanks):
Note: rivers are basically everywhere in japan, so if you want to find a nice, rural one, choose a train line and ride it until you can't see any buildings taller than 2 floors. I'm only gonna list my favorite one.
1. Shukugawa. The river to end all rivers, basically my childhood memories. Take the hankyuu-kobe train line to Shukugawa (https://goo.gl/maps/EqDgmUj8PFJ2), change to  the hankyuu-koyo line and ride it to the next stop called Kurakuen-guchi (https://goo.gl/maps/RL9BaUA9rZF2). Walk along the river next to the station and have fun.