A Gift for My Beloved
Requirements
Manny is leaning against a post during the day, or leaning against a different post at night.
Walkthrough
Talk to Manny to start the quest.
Head to the inn and talk to Prima. Note that talking to her across the desk is as a customer, so walk to the side of the desk and talk to her directly for this quest.
Return to Manny and give him this information.
The next objective is to collect 10 Restless Cricket. Many can be found in the world so there's multiple methods. One method is to cut a lot of grass and quickly pick up crickets as they're revealed. The Ovli Plain northwest of town is probably the closest place with a lot of grass, and it's possible to get all 10 crickets there.
Return to Manny with the crickets, and your reward is a silver rupee.
Tip: If you have done the Slated for Upgrades Side Quest and have Sensor+, take a picture of one of the Crickets. You can then set it as your Sensor+ target for help in finding more of them.
Bonus Tip: Taking a picture of a cricket can be a pain and almost more annoying than just finding them in the first place. If you have done the Sunshroom Sensing Side Quest as well, you can talk to Symin at the Hateno Ancient Tech Lab and purchase creatures pictures for your compendium (at 100 rupees each, getting a random picture each time, can buy in bulk if desired) until you have a picture of a Restless Cricket. You can then set it as your Sensor+ target for help in finding them.