1-3. Kachou, Kekkon Shimashou!! (課長、結婚しましょう!!)
Aoki, who lives with his only daughter after his wife died, has a special hobby of making sweets! One day while handing out his baked goods at work, Mizuno, an unfriendly subordinate, unexpectedly enjoyed the desserts. As a result, Aoki invited Mizuno to his house to deepen his friendship, but as soon as Aoki gave Mizuno a colorful handmade sweet, he proposed saying, "Chief, please marry me!"

4-5. Mizuno-kun no Okashina Sekai (水野くんのオカシな世界)

(Source: Tokuma Shoten, translated)

Note: Chapter count includes one extra.