There's no letter for y. As an alternative, this sound is indicated by doubling the stroke hooked up for the baseline from the vowel letter. With the 7 simple vowels, 4 may be preceded by a y sound, and these 4 were prepared as a dot close to a line.
Take note the dots around the vowels, the 분양 geometric symmetry of s and j in the primary two syllables, the asymmetrical lip at the best-left in the d from the 3rd, and the distinction among First and remaining ieung in the last.
Lax consonants are tensed when adhering to other obstruents due to The reality that the first obstruent's articulation will not be released. Tensing is often noticed in words and phrases like 구 ('entrance') /ipku/ that is pronounced as [ipku].