I am looking for novels or manga where the protagonist travel multiple worlds. They can return whenever they want or at least in accordance to in world mechanics(can only return after 24 hours for example) Here are the examples Saving 80,0000 gold in another world Sasaki and Peep = Sasaki adopted a pet and it turn out he is a interdimensional mage that travel between his original world and Japan. Plot twist is Sasaki's world have psychics, secret organization dealing with them and a magical girl who want to kill them.He is now learning magic, trading between worlds and solving problems with both. The heroines got saved too much they made a mini apocalypse HeroBBS
The Other World Dining Hall Isekai Izakaya Nobu Gate Jietai https://www.novelupdates.com/series-finder/?sf=1&org=496&tgi=21767&mtgi=or&sort=sdate&order=desc https://www.novelupdates.com/stag/world-hopping/?st=1
48 Hours a Day MC enter different worlds for a game and can only exit after he reach the end duration he got to stay in that very world.