Park Hyo Shin 박효신. (2016). Beautiful tomorrow. From the album I am a dreamer. Seoul: Glove Entertainment.
Examples of English phrases incorporated into the main Korean lyrics can be found in 6 of the 12 songs in this album. “Beautiful tomorrow” has the distinction to be both the title and, though appearing only once, a key term of the lyrics (available with translation here). Watch the official music video below or another version of the MV with Hangul, Romanization, and English subs.
You may also want to check out the MVs for other songs from this album featuring Korean-English code-meshed lyrics, including “Home” and “Happy Together”. Another song of note is “Wild Flower” (야생화), first released in 2014 to become one of Park Hyo Shin’s most important works musically and critically and re-recorded as shown in the MV here.